Naval History and Heritage Command

Landing Operations Doctrine

United States Navy
1938

F.T.P. 167

Office of Naval Operations
Division of Fleet Training

United States
Government Printing Office
Washington: 1938

CHANGE No. 1 to
FTP-167

Navy Department,
Headquarters, Commander in Chief,
U.S. Fleet, and Chief of Naval Operations.

Washington, D.C., May 2, 1941.

Landing Operations Doctrine, U.S. Navy, 1938 (FTP-167) was approved on August 5, 1938, for the use and guidance of the naval service, and was made effective on receipt. This publication supersedes "Tentative Landing Operations Manual" of 1935, all copies of which were ordered destroyed by burning.

FTP-167 is intended as a guide for forces of the Navy and Marine Corps conducting a landing against opposition. It considers, primarily, the tactics and technique of the landing operation and the necessary supporting measures therefor. Purely naval or military operations are dealt with only to the extent to which these operations are influenced by the special nature of amphibious warfare.

Change No. 1 to FTP-167 is a complete revision of FTP-167 except for the title page. All pages of FTP-167 (except the title page) bearing Registered Nos. 1-1500 are to be removed and destroyed by burning. Change No. 1 shall be inserted in FTP-167 bearing Registered Nos. 1-1500.

FTP-167, bearing Registered Nos. 1501 and above, has Change No. 1 and the title page entered in process of preparation.

After entry of Change No. 1 to FTP-167 in any copy bearing Register Nos. 1-1500, or after receipt of FTP-167, Register Nos. 1501 and above, the fly leaf receipt shall be executed and forwarded to the Chief of Naval Operations (D.N.C. Registered Publication Section), or District Library, as appropriate.

FTP-167 is a [formerly] confidential registered publication. It shall be handled and accounted for in accordance with the instructions contained in the U.S. Navy Regulations and the current edition of the Registered Publication Manual. It is assigned Class C stowage. It shall not be carried in aircraft for use therein.

It is forbidden to make extracts from or additional copies of this publication without specific authority from the Chief of Naval Operations, except as provided for in the current edition of the Registered Publication Manual.

H.R. Stark,
Admiral, U.S. Navy,
Chief of Naval Operations.

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CHANGE No. 2 to
FTP-167

Navy Department,
Headquarters, Commander in Chief,
U.S. Fleet, and Chief of Naval Operations.

Washington, D.C., August 1, 1942.

Change No. 2 to Landing Operations Doctrine, U.S. Navy, 1938 (FTP-167) is approved. Change No. 2 has been incorporated in the following numbered pages which are transmitted herewith:

Pages:

VII 9 14 34 35 36 41 42 43 45 46 47 48 49 50

51 52 53 54 55 56 57 58 59 60 61 84 85 89 93

95 98 103 161 162 163 164 165 166 167 170 171 174 175 178

181 182 200 214 218 220 228 239 240 241 242 243 244

These pages will be inserted immediately on receipt, and superseded pages will be destroyed by burning, no report of destruction being required.

/S/ R.E. Edwards,
for and in the absence of
E.J. King,
Admiral, U.S. Navy,
Commander in Chief, U.S. Fleet and
Chief of Naval Operations.

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COMINCH FILE
FFI/A10
Serial: 02593

CHANGE No. 3 to
FTP 167

Navy Department,
Headquarters of the Commander in Chief,
UNITED STATES FLEET

Washington, D.C., 1 August 1943.

1. Change No. 3 to F.T.P. 167, Landing Operations Doctrine, U.S. Navy, 1938, is promulgated herewith and is effective upon receipt. It is [formerly] confidential and nonregistered and shall be stowed, transported and handled in accordance with the current edition of the Registered Publications Manual.

2. This change shall be entered as follows:

Pen changes:
Par. 223c, p. 38 - change HYPO to HOW; change PREP to PETER.
Fig. 2, p. 41 - change OPTION to OBOE; change HYPO to HOW.
Par. 230, p. 42 - change "Section VI" to "Section IV."
Par. 322, p. 54 - insert "(FTP 207)" at end of paragraph.
Fig. 16, p. 91 - change "Affirm" to "Able."
Fig. 17, p. 93 - change CAST to CHARLIE in two places.
Fig. 23b, p. 107 - change "Affirm" to "Able."
Fig. 23c, p. 108 - change "Unit" to "Uncle" in three places; change "Hypo" to "How."
Par. 615b, p. 154 - change "par. 553" to "par. 522."
Par. 624c, p. 157 - change "par. 543" to "section IV, Chapter V."
Par. 637a, p. 159 - at end of first sentence, strike out "as described in section III, Chapter V."
Par. 811a, p. 178 - change "see pars. 542, 552c, and 731" to "see section IV, Chapter V."
Par. 833b, p. 188 - change "par. 543" to "section IV."

a. Insert the numbered pages transmitted herewith as Enclosure (A). Superseded pages will be destroyed by burning, no report of destruction being required.

/s/ R.S. Edwards,
Chief of Staff.

--IVa--

[BLANK]

--IVb--

CORRECTION PAGE

--(V)--

[BLANK]

--(VI)--

LIST OF EFFECTIVE PAGES

Chapter I
Landing Operations - General

101. General objectives. -

a. Landing operations may be conducted by naval forces for the following general purposes:

For securing bases for our fleet or components thereof.

For denying bases or facilities to the enemy.

For bringing on a fleet engagement at a remote distance from an enemy main base by causing the enemy fleet to operate in protection of the threatened area.

To cause a dispersion of the enemy fleet by threatening areas vital to his plan of campaign.

For protection of life and property in connection with small wars.

For sabotage.

For the conduct of such other land operations as may be required in the prosecution of the naval campaign.

b. The purpose for which a landing operation is conducted in any given area will influence the nature of the operation, its specific objectives, and the forces to be employed.

102. Types of bases. -

a. Classification and definitions of the various types of naval bases will be found in the War Instructions, U.S. Navy.

b. An advanced base is one established in an advanced location by the operating forces for wartime use. An advanced base established for temporary use in support of landing operations is called a supporting base.

103. Selection of a base. -

a. In the selection of a base consideration must be given to the following factors:

Suitability of the area for the type of base it is proposed to establish.

Geographical location in relation to the theater of operations of the fleet.

Defensive strength and natural resources available.

The operations afloat and ashore required to seize and hold the base.

b. Supporting bases should be within flying range of the proposed landings, and should provide space for the construction of landing fields and sheltered water for the operation of sea planes. Shelter for surface craft and submarines is extremely desirable.

104. Securing a base. - In addition to the purely naval phases of the operation, the securing of a base for our fleet involves the control of all land areas from which the enemy can operate

effectively against the base with infantry or artillery. Ultimately, if the enemy air force cannot be denied by our aircraft and antiaircraft, it will be necessary to conduct additional landings for the purpose of neutralizing enemy air operations against the base.

105. Denying a base. - The denial of a base includes those measures necessary to prevent the enemy from using it. Insofar as landing operations are directly involved, this requires the securing of only such land areas as will enable our forces to operate effectively against the base with infantry, artillery, or aircraft. In this case the enemy force defending the base is an objective of the attacker only to the extent that it interferes with the attacker in occupying such areas and operating therefrom.

106. Illustrative diagram - securing and denying a base. -

a. The difference between securing and denying a base may be considered under two general situations (see fig. 1):

First situation: A BLUE expeditionary force has the task of securing a base for use of the BLUE fleet at A on an island occupied by RED. This task requires BLUE, in the first place, to drive RED from all such areas as B, C, D, E from which RED can operate against the base or its approaches with infantry or artillery and, eventually, from such areas as X or Y from which he can operate effectively against the base with aircraft. At least BLUE must successfully neutralize enemy weapons and aircraft operating against the base from such areas.

Second situation: BLUE has the task of denying the base A to RED. In this case BLUE would have to secure and hold only one area, such as B or E, from which he could operate effectively against the base or approaches thereto with infantry or artillery, or X or Y from which he could operate effectively against the base with aircraft.

b. In planning a landing operation in an area occupied by an enemy force it should be remembered that the task of the enemy will materially affect the probable strength and disposition of his forces. If his task is to deny the base, his force may be relatively weak and largely concentrated in, or prepared to move into, an area which is easy to defend. If his task is to secure the base for his own use, his forces will probably be of greater strength and more widely dispersed.

107. Landing raids. - Landing raids are generally made for the purpose of destroying enemy facilities and establishments, such as batteries, bridges, docks, supplies, aircraft, etc., or for harassing defense forces, diverting attention from operations in other localities, and effecting division of enemy forces. Such operations depend largely for success upon rapidity of movement and surprise, and normally involve relatively small forces, a limited advance inland, and a quick withdrawal. They may be conducted in connection with other landings or as a separate operation.

108. Land in the tactical control of sea areas. -

a. The ability of naval forces to maintain themselves in a given area may be dependent, from a tactical as well as from a logistical point of view, upon the occupation or control of the land areas lying within or adjacent to the theater of operations. Under modern conditions, certain types of bases have been moved from the realm of logistics to the realm of tactics; that is, from the line of communications to the line of battle.

b. Due to the importance of aircraft in fleet engagements, the relatively small number and vulnerability of carriers, and the possibility of shore-based aircraft operating with and augmenting the strength of our own or the enemy fleet, territory which otherwise might have no strategical or tactical value assumes an important role as possible air bases.

c. To a lesser extent submarine bases may be considered in the same category as air bases.

d. When the successful prosecution of the naval campaign requires the fleet, or portions thereof, to operate in a theater within effective flying range of enemy territory, the preliminary naval operations may revolve around a contest for the available land within or adjacent to the area. The entrance into and the securing of the initial foothold in such a theater of operations is hazardous and involves landing operations of a difficult nature. Under such conditions, the naval operations during the preliminary phases may be in the nature of a naval reconnaissance involving landings made with the view of securing information and seizing unoccupied or lightly held territory which later may be occupied in force and, ultimately, used as a base for further operations. (See par. 119, Supporting Bases.)

109. Small wars. - The extended and skillful use of automatic weapons by unorganized and irregular forces, even though relatively weak, may result in heavy casualties during a landing at localities occupied by such forces, unless the landing is conducted in accordance with sound tactical principles. While the doctrines herein enunciated are intended primarily as a guide in major operations, they apply equally to small war situations, with due allowance made for the character of the forces engaged and the necessity of safeguarding life and property insofar as possible.

110. Superiority of force essential. -

a. Operations involving landings against opposition are among the most difficult of military operations, and superiority of force, particularly at the point of landing, is essential to success.

b. Numbers alone cannot afford the required superiority. There must also be that effectiveness which is obtained by proper organization, equipment, and training of the naval and marine forces involved, not only for the special operation of landing but also for the conduct of the subsequent advance inland from the shore line where decisions will have to be made and executed under the stress of battle to meet conditions that are more adverse than those ordinarily prevailing in a purely land attack.

c. In this connection, however, it should be recognized that the attacker may have certain very definite advantages as well as disadvantages in the conduct of such an operation, as compared to a purely land attack. In particular, he has the initiative which permits him to choose his objectives and lines of approach toward them. The great mobility of his ships, compared to movements overland, enables the attacker to concentrate his forces quickly while comparatively large enemy forces may be immobilized by demonstrations or a threat of attack elsewhere. Through the mobility of reserves retained afloat, the attacker has an excellent opportunity to exploit initial successes ashore. The relatively rapid movement of the boats in making the approach to the shore line compensates in part for the lack of cover that is usually available on land.

111. Naval forces. -

a. An extensive overseas expedition presupposes marked superiority on the sea and in the air within the area of, and during the time required for, the operations. Such superiority does not necessarily preclude all possible damage to vessels of the expedition by enemy action, but it must be sufficient to insure a reasonable degree of protection to transports accompanying the expedition while in passage and during the progress of the operations. Consideration should be given to the employment of second-line ships for convoy duty and gunfire support tasks.

b. Large ships stopping in the open sea and troops disembarking in small boats are extremely vulnerable to attack by submarines and aircraft. Careful consideration, therefore, must be given to the removal or neutralization of the submarine and air menace prior to the start of the actual landing. In situations where the effective neutralization of these enemy activities cannot be accomplished initially, or when preliminary landing operations are necessary to secure protected waters for unloading transports (fig. 11, ch. I), it may be desirable to employ destroyers for transporting troops, as well as for towing the required landing boats, from the transports to the point of embarkation into the landing boats.

c. The successful assault of a defended shore line requires a heavy expenditure of naval ammunition, with the consequent wear on ships' guns. It may involve the loss of a number of ships and aircraft. The initiation of such an operation is not justified unless the naval situation fully warrants the assignment and possible loss of the required vessels and air forces and the expenditure of the necessary ammunition.

d. It is particularly desirable to include a considerable number of destroyers in the forces, due to their suitability for antisubmarine security, control vessels, and possible troop transports for limited distances. They are also very effective when boldly employed against enemy defenses located close to the beach.

112. Marine forces. -

a. Unless the landing forces are unquestionably superior in infantry, as well as artillery and other supporting arms, to the enemy forces that may be expected to oppose the landings and the subsequent operations on shore required for the accomplishment of the mission, the initiation of such an operation is not justified.

b. The operations ashore as well as the landing must be adequately supported by marine aircraft or, in their absence, by naval aircraft.

113. Tasks of opposing forces. - If, by reason of the task of the defender, the coast line or amount of territory to be defended is great in proportion to the strength of the defender, he will have to disperse his forces or leave certain portions of the coast undefended. The attacker may thus be able to concentrate, by reason of the superior mobility of his ships, an overwhelming superiority at the point of landing. Under such conditions, particularly if the task of the attacker permits him to assume the defensive after landing, the operation may be undertaken without as great superiority as would be necessary where the territory is restricted, the landing beaches are limited, and the task of the landing force requires offensive operations after landing.

114. Time element in preparations of defense. - Time is an important element in preparing an effective defense. A comparatively short delay, which would give the enemy time to organize and coordinate his infantry and artillery fires and prepare defensive works, would necessitate the employment of a much larger attacking force against the same defending force. It is important, therefore, that properly trained naval and marine forces be available and prepared to initiate at an early date after the outbreak of hostilities any landing operation that may be decided upon.

115. Arrival of enemy reinforcements. - The possibility of enemy reinforcements, particularly air forces, arriving during the course of the operation requires careful consideration in the estimate of the relative strength, and influences the selection of the time of arrival of the attacking force in the landing area.

116. Replacements. - Provisions should be made for adequate replacements, so that experienced units may be maintained at full strength. Since casualties in a landing operation are likely to be high in the initial phases, estimates of replacements to accompany the force should be liberal.

Preliminary operations. - Prior to initiating an operation involving a landing against serious opposition, the desirability of organizing advance or reconnaissance forces for the conduct of certain preliminary operations should be given consideration. The following preliminary operations in connection with proposed landings may be desirable:

Reconnaissance.
Seizure of a supporting base.
Operations against defending aircraft.
Operations against naval defense forces.

118. Reconnaissance. -

a. Information to be obtained. -

1. Information regarding a theater of operations may be considered under two general heads, namely, Naval and Military.

2. Naval information is obtained for the purpose of determining the enemy naval dispositions in the theater of operations; verifying and supplementing existing hydrographic and meteorologic data; determining, from a navigational standpoint, the suitability of beaches and sea areas required for the conduct of a landing; locating mined areas, underwater obstacles, and other obstructions; selecting suitable approaches to landing areas; preparing sailing directions; and establishing necessary aids to navigation.

3. Military information deals with the nature of the terrain in the proposed zone of operations and the enemy disposition ashore, including defensive works, strong points, machine gun and artillery positions, location and intensity of defensive barrages, landing fields, gassed areas, location of reserves and their routes of advance, supply and ammunition facilities.

b. Necessity for reconnaissance. -

1. It is a sound principle in the conduct of landing operations to avoid landing against strongly organized positions unless such action is the only means of carrying out the assigned task within the time available. In general, such organized positions can be located only by adequate and thorough reconnaissance.

2. There is a notable lack of information on charts and in existing sailing directions in regard to landing conditions for small boats. There is a further possibility that the enemy will place underwater obstacles and other obstructions on or near available landing beaches and

approaches thereto. Information in regard to beaches, therefore, will have to be secured largely through active reconnaissance.

3. On an inadequately charted coast line, with ordinary navigational aids destroyed by the enemy, the safe navigation of the attacker's ships requires careful and detailed reconnaissance. Under some conditions, a limited hydrographic survey of the coast and the establishment of necessary aids to navigation may be required.

4. The necessity for conserving and making the best use of the limited supply of naval ammunition renders it desirable that beaches be reconnoitered before being shelled by ships' guns in order to determine whether or not they are being held by the enemy. It is also desirable to locate strong points in the enemy position, and to chart landmarks which will enable firing ships to identify their target areas.

5. Before landing relatively large bodies of troops, particularly on small islands or in other restricted areas, it is important to determine by reconnaissance if beaches have been, or are likely to be, gassed.

c. Means employed. -

1. To gain the desired information, surface craft, submarines, aerial observation and photography, and landing parties are employed.

2. Aerial photographs and direct observation from the air and sea will give fairly complete information in regard to certain types of fieldworks on shore but will give very little information as to whether or not they are occupied. Particularly dangerous emplacements, such as machine-gun positions, may be so well camouflaged as to be completely invisible. As a rule, the number and location of defensive weapons can only be determined, and then with difficulty, by causing them to open fire, which normally they will do only when a landing seems imminent. Against an alert enemy, therefore, the attacker will have to depend upon landing parties or demonstrations to gain information regarding the enemy's strength and dispositions on shore. The landing parties may consist of agents, patrols, or reconnaissance in force. (See ch. IV, sec. VI, Reconnaissance Patrols.)

d. The intelligence plan. - After making a study of existing data on the proposed theater of operations, an intelligence plan should be prepared in which is listed the additional information, naval and military, required for the conduct of the operation. This intelligence plan forms the basis for determining the size, composition, and tasks of the reconnaissance force dispatched to the theater of operations for the purpose of collecting the necessary information.

e. The principle of surprise. - In the execution of the intelligence plan for a specific landing operation, care must be taken not to divulge the intentions of the attacker, and certain landing areas and beaches, which are not to be used, should be reconnoitered as thoroughly and with the same means as those at which landings are planned.

f. Detailed reconnaissance of a landing area. - In connection with the detailed reconnaissance of a particular landing area, see paragraphs 209 and 210.

119. Supporting bases. -

a. In many theaters of operations, it will be extremely difficult for the defender to occupy all of the available land areas in force. Certain areas will be strongly fortified and others will be more lightly held or even unoccupied. If it is necessary to seize a fortified position in such an area, it will generally be advisable, if not mandatory, to operate step by step, seizing first the weakly defended areas for use as supporting bases in the subsequent landings against the fortified positions.

b. If suitable areas are available for the purpose, the establishment of one or more supporting bases may furnish the following advantages in the execution of the main attack:

Permits naval aircraft to operate from landing fields and reduces the risk incident to carrier operations.

Permits the employment of seaplanes.

Permits employment of the aviation of the landing force.

Denies landing fields and other facilities to the enemy.

Affords shelter for vessels before and during the course of the subsequent operations.

Affords a rendezvous and a point of departure for subsequent landings.

Facilitates the storage and distribution of supplies.

c. A supporting base will usually be within bombing range of an enemy base or possible base. Under such conditions, the seizure and occupation of the supporting base, and the installation of the necessary landing fields and facilities, is a delicate problem and the operation may require a considerable period of time. The initial operation may be a landing in force, or a foothold may be secured by advance or reconnaissance forces. In the latter case, the garrison and base facilities may be gradually built up by the subsequent landing of troops and matériel

in relatively small increments. It will be safer to fly planes in from carriers after adequate landing fields and air and antiaircraft protection have been provided, rather than to attempt landing crated planes and setting them up under hostile bombing attacks. The enemy may be expected to bring the full strength of his air units against the establishment of a supporting air base.

120. Operations against defending aircraft. -

a. Operations against enemy aircraft, preliminary to a landing, may include aerial combat, bombing and strafing planes on the ground, and gassing, bombing, and shelling landing fields and their installations.

b. The enemy will, if possible, utilize a large number of landing fields; camouflage will be employed to the fullest extent to protect his establishments; dummy planes will be displayed; real planes will be widely separated and camouflaged. Such protective measures on the part of the enemy require careful reconnaissance before successful attacks can be launched. The restriction of hostile air activities by rendering a considerable portion of his landing fields unusable through bombing attacks will require extensive operations and a heavy if not prohibitive expenditure of bombs. Therefore, such bombing operations should be limited to landing fields definitely known to be occupied.

c. Carrier-based planes are at a distinct disadvantage in conducting this type of operation compared to land-based planes. For this reason, if a supporting base is not available to the attacker, it may be advisable to restrict preliminary air operations of carrier-based planes to necessary reconnaissance, in order to insure superiority at the critical time of landing.

121. Operations against naval defense forces. -

a. The naval defense forces of a base, having the mission of furnishing information of the attacker's movements and inflicting damage to his ships and small boats transporting troops to the beach, must be cleared from the sea areas required for the conduct of the operation, or effectively neutralized during the course of the landing.

b. In addition to screening and patrolling the station and maneuver areas of the attacking force during the landing, advance forces may be given the task of operating against the naval defense force prior to the landing with the view of clearing the required area of surface patrol craft and reducing the number and effectiveness of enemy submarines.

c. At night, patrol vessels constitute one of the defender's principal means of securing information as to the movements of the attacker's ships. To secure this information, they have to approach closely and attempt to identify every vessel maneuvering on the coast. For this reason, destroyers of the attacker operating at night against naval defense forces have an excellent opportunity of making contacts with enemy vessels and locating their patrol areas. Operations in such areas for several nights prior to the landing should result in material losses to the naval defense force and reduction in its effectiveness by compelling the enemy vessels to adopt a less aggressive attitude.

122. Organization of advance forces. -

a. The composition of advance forces will depend upon the tasks assigned and the probable enemy forces in the theater of operations. Advance forces should be dispatched at such time as will permit the main operation to be executed without unnecessary delay.

b. Specially trained marine personnel and suitable boats for reconnaissance tasks should accompany the force for the conduct of necessary shore reconnaissances. When the advance force is given the task of securing a supporting base, a suitable landing force should be made a part of the advance force, or available to it, for use when the occasion arises.

123. Types of operations. - The seizure of an area defended by hostile forces may involve the following coordinated operations:

The main landing;
One or more secondary landings; and
One or more demonstrations or feints.

124. The main landing. - The main landing is that upon which the ultimate success of the tactical plan depends. In the assignment of troops, ships, and aircraft, it has first consideration and must be provided with the forces necessary for success. The detachment of any forces from the main landing for the conduct of a subsidiary operation is only justified when the results to be reasonably expected from the latter are greater than if these forces were used in the main landing. In some situations, consideration should be given to making two or more landings in force, with the view to exploiting the landing which is most successful.

125. Secondary landings. -

a. Secondary landings are those made outside the immediate area of the main landing which directly or indirectly support the main landing. They may be made prior to, simultaneously with, or subsequent to, the main landing.

b. Secondary landings are usually made for the purpose of seizing and holding areas which are desirable for operations in connection with the main landing, or which may be used by the enemy in opposing the main landing. Secondary landings may also be made for the purpose of diverting enemy reserves, artillery fire, or aircraft support from the area of the main landing. Such landings may also cause delay in starting the movement of the general reserves, or local defense forces from other sectors, to oppose the main landing.

c. The early entry into action of land-based artillery and aircraft may be necessary in order to provide adequate support for the main landing or the operations on shore. Where suitable areas for landing fields or artillery positions exist outside of the area of the main landing, consideration should be given to the early seizure of such areas by secondary landings.

d. Secondary landings made for the purpose of causing the movement of hostile reserves from the main landing area require, as a rule, a greater proportional force than those seeking to hold enemy forces in place or retard their movement. In the former case, sufficient force must be employed to overcome the local defense forces and gain a success which threatens a point important to the defender; otherwise, he probably will not move his reserves.

e. The term "secondary landings" should not be used in plans and orders, as these landings constitute an important part of the operation as a whole. The forces assigned these tasks must carry them out with the same determination that characterizes the main landing.

f. In some situations, the development of the subsequent operations may make it advisable to exploit a secondary landing rather than the main landing, consequently this should be considered when selecting areas for secondary landings.

126. Demonstrations. -

a. A demonstration, or feint, is an exhibition of force, or movement, indicating an attack. Demonstrations are made for the purpose of diverting enemy reserves, artillery fire, surface craft, submarines, or aircraft support from the area of the main landing, or the retarding of the movement of enemy forces thereto.

b. In order further to deceive the enemy as to the location of the main landing, demonstrations may be conducted and coordinated with secondary landings. A demonstration alone, however, may often be more effective than a weak secondary landing, particularly in delaying the movement of enemy forces toward the area of the main effort. The effectiveness of a weak landing is largely lost as soon as its weakness is discovered, while a show of force constitutes a continuing threat and may hold in place comparatively large enemy forces for considerable periods of time. In order to produce the greatest effect, the mobility of ships should be utilized in such operations to threaten a number of points and thus immobilize enemy forces over a large area.

c. Demonstrations have no territorial objective but they should threaten areas of importance to the enemy. They should be coordinated as to time, and directed at points so distant from the main landing that they will contain the enemy forces stationed at or drawn to such points, and prevent them from opposing the main landing. This coordination as to time and distance is particularly important where it is desired to prevent the participation of the enemy aircraft, surface vessels, and submarines in the operations involved in the main landing.

d. Demonstrations conducted in conjunction with and in the vicinity of an actual landing are effective in causing a dispersion of enemy artillery fire. Shore batteries generally have a "normal zone" covering one or more beaches and a "contingent zone" covering other beaches or areas. The defensive artillery plan will generally provide for a concentration of all batteries within range of a designated point. A few boats approaching a beach, particularly when accompanied by smoke and some gunfire, should make all enemy batteries, within whose normal zone the beach lies, open fire on that particular beach or boats, rather than joining in a general concentration on the actual landing. Such demonstrations are particularly desirable when the main landing is conducted on a comparatively narrow front.

e. Demonstrations may be conducted in connection with reconnaissance prior to a landing in order to cause the consumption of the enemy ammunition and chemical supplies, the disclosure

of his strength and dispositions, artillery positions, barrages, gassed areas, and landing fields, and further the wearing down of his air forces.

f. From the foregoing, it may be seen that demonstrations or feints may be made to contribute greatly toward the gaining of tactical surprise.

127. Surprise landings. - Rubber landing craft, track landing vehicles, and other special types of boats, as well as parachute troops, and troops transported during the night from a distant base by patrol planes or large commercial clipper planes, should be utilized to the fullest extent to execute surprise landings at points where, due to the nature of the beaches or terrain, landings would not ordinarily be expected. These landings may be in connection with or part of the main or secondary landings and should be made in accordance with the same principles and for the same purposes as previously set forth in this section.

128. The beachhead. -

a. The first consideration in the conduct of operations on shore after the landing has been effected is the seizure of a beachhead of sufficient extent to insure the continuous landing of troops and matériel, and to provide the terrain features and maneuver space requisite for the projected operations on shore.

b. The establishment of a beachhead enables a commander to maintain control of his forces until the situation ashore has developed and he has sufficient information on which to base his plans and orders for further operations.

c. As a matter of security, it will be necessary to clear the beachhead of enemy resistance. It should be kept in mind, however, that the establishment of a beachhead is not a purely defensive measure. It has the equally important object of insuring further advance inland if required to accomplish the mission of the force. Consideration should be given, therefore, to the early seizure of terrain features which will facilitate this advance by including them in the beachhead or making them the objective of a special operation. Consideration should also be given to depriving the enemy of terrain features which are most advantageous in the defense.

129. The force beachhead line. - This is an objective prescribed for the purpose of fixing the limits of the beachhead. It is not necessarily a defensive position to be occupied and organized as such. It is, however, a tentative main line of resistance in case of counterattack prior to the advance from the beachhead, and it is occupied and organized to the extent demanded by the situation. (See fig. 2.)

130. The exploitation line. -

a. This is a line beyond the beachhead line to which reconnaissance and security detachments will be pushed by units occupying the beachhead line. It provides a zone in which active reconnoitering will be conducted on the initiative of such unit commanders and, at the same time, prevents a greater dispersion of the force as a whole than is desired by the force commander. (See fig. 2.)

b. Reconnaissances beyond the exploitation line will partake of the nature of reconnaissances in force launched by specific orders against designated points or in designated directions.

c. In the event of the occupation of the beachhead line as a defensive position, the exploitation line constitutes the limit of the outpost positions.

131. Extent and form of the beachhead. -

a. The beachhead should be of sufficient depth and frontage to secure the landing from ground-observed artillery fire. Usually this will be possible only with comparatively large forces. A landing force manifestly cannot overextend its units or subject its flanks, beach establishments, and land communications to attack until the enemy situation has been developed. The depth and frontage of the beachhead will be dependent, therefore, upon the mission, the size of the force engaged, the nature of the terrain particularly as regards natural obstacles, and the probable enemy reaction.

Figure 2 shows diagrammatically how terrain features may modify the form of the beachhead, and the extent to which the beachhead line may have to be occupied under various

conditions in order to insure the desired security of the shore establishments. In figure 2-a, the terrain is assumed to be suitable for maneuver throughout its whole extent. In figures 2-b and 2-c, the effect is shown of certain impassable obstacles, which may be encountered in a variety of forms and combinations. Figure 2-d shows a beachhead where it is necessary to land in a town. This latter situation might arise in the seizure of a town as part of a major operation or in connection with a small war where a beachhead, in addition to its normal functions, would afford an immediate security zone for civilians. In most situations of this kind it would be advisable to land outside the town even though only very weak resistance is anticipated.

132. Successive objectives. - Successive objectives may be designated to coordinate the advance from the beach to the beachhead line. Such objectives have the advantages of permitting reorganization of attacking troops, passage of lines, coordination of field artillery and ships' gunfire with the advance, and facilitating the execution of an appreciable change in direction of the attack. Objectives entail a certain delay and should not be prescribed unless actually needed for a definite purpose.

133. The artillery control line. -

a. This is a line short of which the field artillery does not fire except on request of infantry commanders, and beyond which the advance is supported by the bulk of the field artillery. Its introduction is often desirable in order to permit artillery to open fire immediately upon landing without danger to friendly troops.

b. The position of the artillery control line is fixed after consideration of the probable position of the infantry at the time the artillery is ashore and in position to open fire. If suitable terrain features exist, the artillery control line should be located a safe distance beyond an infantry objective, which can easily be defined and readily identified on the ground by both infantry and artillery. If no such natural features exist, the artillery control line should be located at such distance from the beach that the advanced infantry elements will not, in all probability, have reached the target area at the time it is estimated that the artillery will open fire.

c. Main reliance must be placed in ships' gunfire for support of the attack up to the artillery control line, as field artillery will not be in position to fire short of this line unless the attack is stopped or materially slowed down before the artillery control line is reached.

134. Intermediate beachhead lines. -

a. Subordinate commanders may find it desirable, particularly where beaches are not contiguous, to designate intermediate beachhead lines in addition to the successive objectives prescribed by higher authority, with the view of protecting the beaches from aimed small-arms fire. The depth of such intermediate beachheads will be largely dependent upon the formation of the terrain adjacent to the beach. If there is a bluff or ridge close to the shore line, a comparatively shallow intermediate beachhead may suffice; if the terrain inland from the beach is an open, fairly uniform slope, an intermediate beachhead of from 1,000 to 1,500 yards may be necessary to accomplish the desired purpose.

b. When intermediate beachheads are prescribed, they are designated "Battalion beachhead," "Regimental beachhead," etc., according to the organization for which prescribed.

135. Establishing the beachhead. -

a. In a landing operation, troops must clear the beach rapidly; there must be no delay at the water's edge. This requires, in the first place, that leading units be landed in assault formation as fully deployed as the available boats permit. Once landed, every individual must thoroughly understand that he must first clear the beach and then move rapidly inland or in the designated direction.

b. Assault units push the attack to their designated objectives without waiting for the advance of units on their flanks. Reserves are utilized to cover the flanks of advanced units rather than holding up the attack for a uniform advance on the whole front. If a unit is landed on the wrong beach, its commander will initiate such action as will best further the general scheme of maneuver.

136. Advance from the beachhead. -

a. The desirability of establishing a security zone around his shore base should not lead a commander to adopt a passive attitude. Unless the mission is accomplished by the securing and holding of the beachhead, active, aggressive action provides the surest means of carrying out the mission and will often afford the best protection to the beach establishments.

b. The advance from the beachhead line, however, may entail the breaking of one or both flanks from physical contact with the shore, the establishment of shore lines of communication, and entering into a phase of war of maneuver. Under such conditions, the securing of a beachhead may be followed by a period of stabilization during which the necessary regrouping of forces may be effected and information of the hostile dispositions secured. Reconnaissances by air forces and ground troops should be pushed vigorously so that the delay on the beachhead line may be reduced to the absolute minimum.

137. The landing area. - The landing area comprises the sea and land areas required for executing the landing and establishing the beachhead. Its selection is governed by the following principal factors:

Mission.
Enemy dispositions.
Number and types of beaches and approaches thereto.
Suitability of terrain for shore operations (including the establishment of the beachhead and contemplated advance therefrom).
Station and maneuver areas for naval vessels.
Configuration of the coast line.
Time element.
Weather conditions.

138. Mission. - The area selected must be such as to assure the landing of sufficient troops (after making due allowances for losses before and after landing) at a place from which they can reach their objective and accomplish the mission for which the landing was undertaken.

139. Enemy dispositions. -

a. A landing area in which the defender has been able to occupy and strongly organize the available beaches should be avoided if it is possible to carry out the mission by landing at beaches undefended or less strongly held.

b. Where the defender is organized in depth, with natural obstacles and other means of defense, the successful conduct of a landing operation will require an enormous expenditure of ammunition, far beyond that ordinarily supplied to combat vessels. Such an operation should never be undertaken unless sufficient ships, planes, and ammunition are available effectively to neutralize the enemy weapons.

c. The probable location of enemy general or local reserves, and the facility and speed with which these reserves can be thrown into action to oppose the landing or the advance inland, are important elements in the selection of a landing area. Consideration should be given, therefore, to the routes and means of communications available for these reserves to the various landing areas, the possibility of the attacker interfering with their movement by air attack and interdiction fires, and the presence of terrain features, such as defiles and natural obstacles, favorable to employment of these reserves in opposing the advance.

140. Beaches. -

a. A beach is that portion of the shore line normally required for the landing of a force approximating one infantry assault battalion. It may be, however, a portion of the shore line constituting a tactical locality, such as a bay, to which may be assigned a force larger or smaller than a battalion.

b. Favorable beaches, from a physical standpoint, are those which permit the beaching of small boats close to the shore line and the rapid disembarking and movement inland of troops and equipment without undue interference from weather conditions or navigational difficulties.

c. Open beaches on the weather side where surf is breaking, or is likely to break during the course of the operation, are especially unfavorable, particularly where there are rocks or coral, unless landing boats especially designed to cross these obstacles are available. The landing of a large force with its impedimenta may extend over several days, and this, together with the necessity of maintaining lines of supply, requires that certain beaches provide suitable conditions for continuous landings throughout the operation.

d. Gently shelving beaches, or those having offshore reefs, causing small boats to ground at a considerable distance from the shore line, are unfavorable, as the time of disembarking and deploying is lengthened, with consequent increase in the effect of hostile fire. The use of shallow draft lifeboats or rubber boats will be found advantageous when, because of tactical considerations or hydrographic conditions elsewhere, a landing on this type of beach is desired.

e. Approaches to the beach should be free, under all conditions of tide, from natural or artificial obstructions to navigation, and it is particularly desirable that there be sufficient room to seaward to permit the boats to deploy into their attack formations before coming under effective artillery or small-arms fire. Narrow entrances between islands and channels in reefs prevent this early deployment and greatly increase the effectiveness of the defender's fire.

f. Some of the beaches must provide suitable landing conditions and routes inland for wheeled vehicles and tractors. Such beaches may be captured initially or in subsequent operations. Other beaches may be suitable for landing infantry and pack artillery only. In this connection, it should be recognized that determined foot troops can negotiate precipitous slopes and that such slopes will often offer dead spaces from enemy fires. Landing conditions at the foot of rocky cliffs, however, are often bad and landings may be possible only in calm seas.

g. The area around a beach in which the defender can place weapons for direct aimed fire on the beach will be limited by the configuration of the ground. When such areas have a depth of several hundred yards, the immediate landing is more difficult because of the large zone which has to be neutralized. Shallow areas are advantageous in reducing the size of this zone and permitting the attacker to deprive the defender of observation on the beach after a relatively short advance. Woods which the defender has not had time to clear, or a bluff close to the beach, have certain definite advantages in executing the actual landing, provided the advance of necessary combat equipment is not seriously impeded. Such features may, however, render more difficult the support by naval gunfire of the subsequent advance inland.

h. The number of beaches required for an operation is dependent upon the size of the attacking force, the scheme of maneuver, and the amount of resistance expected. A landing area with a large number of suitable beaches is particularly desirable, even for a comparatively small force, as it causes a dispersion of the defender's efforts and permits the attacker to land on as broad a front as is commensurate with his strength. Such an area also favors tactical surprise, as it offers the attacker a choice in the selection of beaches, and the defender is unable to determine the exact point of landing until the boats have approached close to the shore.

i. The shore line need not be suitable for landing throughout its entire extent, provided the various beaches permit the units landing thereon to be mutually supporting and a portion of the beaches permit the timely landing of the required equipment.

j. Beaches not otherwise suitable may be utilized for landing troops in rubber boats, amphibian tractors, or other special type boats. Such special equipment should be utilized to the fullest extent practicable for the execution of surprise landings, and to assist main landings by pressure at points which, because of the nature of the coast line, are lightly held by the enemy.

141. Suitability of terrain for shore operations. -

a. The influence of the terrain on the shore operations is the same as in ordinary land warfare. The proposed zone of advance should be critically examined as to its suitability for the contemplated operations, paying particular attention to the road net, natural obstacles or defiles which have to be forced, observation for both defender and attacker, maneuver room for the force engaged, and landing fields which permit the early entry into action of our land-based aircraft.

b. In connection with the location of the landing area in relation to the final objective of the shore operations, consideration should be given to the advantages inherent in a movement along the coast line. The sea affords protection to at least one flank, and such a movement greatly facilitates the supply problem in that the shore base may be shifted as the action progresses, resulting in shorter and more easily protected lines of supply. This type of operation also compels the defender to fight on lines perpendicular to the beach and permits reinforcement of field artillery by ships' guns firing under the most advantageous conditions. Too much reliance, however, should not be placed on this support except in areas adjacent to the beach and visible from seaward.

142. Station and maneuver areas for naval forces. -

a. The naval forces should have station and maneuver areas free from mines and obstructions, and with suitable approaches thereto, in which troops may be safely disembarked and from which the type of fire demanded by the situation may be delivered. The areas must be conveniently located with respect to the available beaches.

b. Water deep enough for maneuvering vessels close inshore is desirable, as it enables ships accompanying the boats to stand well in and deliver their fire at short range. This permits the most effective support during the approach of the small boats and the initial landing.

c. Flanking fire in support of a landing is generally more effective than that delivered from the front, as it tends to enfilade the defender's position and permits small boats carrying troops

to approach closer to the area being shelled. Sea areas from which this type of fire can be delivered are, therefore, extremely desirable.

d. A sheltered transport area will materially decrease the time required for unloading troops and equipment and will lessen the danger of the operation being interrupted by bad weather.

e. Water with a depth and bottom suitable for anchoring marking ships or buoys is a desirable feature. It may be advantageous in some cases to anchor transports or even firing ships. Water of less than 10 fathoms furnishes considerable protection against large submarines, provided the shallow depth extends far enough to keep enemy submarines outside of maximum torpedo range. This depth of water, however, does not furnish complete protection from small submarines, and is favorable for enemy mining operations.

f. If a convenient supporting base is not available for anchorage and protection of the naval forces during the period elapsing between the initial landing and the securing of a suitable new base, it is highly desirable that the landing and operations ashore be planned with a view to securing a sheltered anchorage as quickly as possible.

143. Configuration of the coast line. -

a. Favorable landing conditions are usually found in harbors, bays, and indentations in the coast line. Such formations, however, favor the concentration of enemy artillery fire in the entrances and, furthermore, permit the defender to bring flanking fire upon the boats from automatic weapons and antiboat guns from the shores flanking the entrance. Enemy weapons so located must be neutralized by either naval gunfire or the leading element of the landing force before the boats making the main landing come within effective range of such flanking fire.

b. Land projections are favorable to the attacker in that they facilitate the delivery of flanking fire by ships' guns and permit the attacking units to protect both flanks by resting them on the water's edge. At the same time, the base of a peninsula may afford the enemy a strong defensive position which will block progress inland. The seizure of such projections as a supporting measure for other operations may be advisable.

c. A chain of small islands offers certain advantages as a landing area. The delivery of naval gunfire, particularly counterbattery, is facilitated, and the operation may be conducted step by step, each island as it is seized becoming a base for further operations. The islands may be mutually supporting by small-arms or artillery fire, but the employment of general reserves by the defender for opposing the landings on the various islands may be difficult or entirely impossible.

144. Time element. - Certainty of getting ashore is of first consideration, but a successful landing avails nothing if the landing force, by reason of distance or difficulties of the terrain, is unable to reach its objective in time to carry out its mission. The time element, therefore, is important in the selection of the landing area. If time is limited it may be necessary to land close to the objective regardless of enemy dispositions. With more time available, the landing may be made in an area where the beaches are less heavily defended, but requiring more extensive shore operations for the carrying out of the mission.

145. Weather conditions. - Careful study must be made of the weather conditions in the contemplated theater of operations. Operations that may be feasible at one season of the year may be impracticable at another due to weather conditions, such as prevalent high winds which may render landings impossible, the likelihood of storms interrupting ship to shore communications, or rains rendering land operations difficult. Surf and reefs may be negotiable at only one stage of the tide and conditions may vary within the same general area.

146. Final selection of landing area. -

a. Landing areas having the best beaches and the most favorable approaches inland will probably be those most heavily defended by the enemy. Conversely, landing areas with unfavorable beaches and easily defended avenues of approach inland will be less heavily defended.

b. The final selection of the landing area will generally be a question of deciding between these conflicting conditions. A correct decision demands a careful estimate of the situation, involving not only a study of the physical features of the beaches but a thorough knowledge of the capabilities and limitations of the opposing forces and a careful computation of time and space.

c. As a rule sufficient information on which to base a decision will not be available until after a thorough reconnaissance has been completed.

147. Frontage of attack. -

a. An important consideration in formulating a scheme of maneuver is the frontage to be covered by the landings and the subsequent advance inland. Necessarily, the frontage of the landing is dependent, to a large extent, upon the number, type, and relative position of the beaches available in the landing area. An almost equally important consideration, however, is the strength and equipment of the attacking force. During the initial stages of the landing, ships' guns constitute the artillery of the attacking force. This force must be considered therefore, as comprising two elements of major importance, namely -

The landing force.
Naval gunfire.

b. The landing force. -

1. It is desirable to attack on a wide front in order to increase the speed of landing and to cause a dispersion of the defender's efforts, but the attacking force must not itself overextend. It must observe the principle of concentration of effort and assign sufficient forces to the various tasks to insure their success.

2. Units comprising initial assault echelons are particularly apt to become disorganized during and immediately after the landing, and they cannot be expected to make deep penetrations against strong opposition. It is often desirable, therefore, to have leading assault units secure a limited objective or intermediate beachhead and cover the landing of fresh troops with which to carry on the attack.

3. In many cases landings will not be made on the entire front of the beachhead. This will result in the zone of attack increasing in width as the advance inland progresses. The scheme of maneuver, therefore, must provide for the introduction of additional units in the assault from time to time in order to take care of this increased front.

4. Sufficient reserves must be kept in hand to insure the exploitation of successes and to continue the attack to the final objective. But an operation which apparently requires all of the attacker's forces for securing the initial foothold on the beach is rarely justified.

5. The foregoing factors require organization in depth, and units should be assigned frontages which permit a depth of formation commensurate with the effort expected of them; that is, according to the depth of advance, the nature of the hostile opposition, and the assistance to be expected from or given to neighboring units. Consideration must be given not only to the frontage of the landing but to the frontage to be eventually covered by the unit.

6. For frontages applicable to various subordinate units, see chapter IV, section III.

c. Naval gunfire. -

1. Probably the most difficult decision in formulating the scheme of maneuver is that pertaining to the frontage which can be effectively covered by the fire of the available ships, and it is here that the judgment and responsibility of the commander is put to the severest test. In deciding this question, consideration must be given to: First, the devastating effect of the fire of relatively few machine guns when firing under advantageous conditions; second, that an attack against such weapons has little chance of success unless adequately supported by artillery; third, that a landing operation cannot be stopped and resumed at will, and, as a rule, only one chance for success is offered.

2. In order to provide this essential artillery support, the scheme of maneuver must observe the principle of concentration of effort for the naval gunfire as well as for the landing force, by limiting the landings to frontages commensurate with the amount of supporting gunfire available. Where the number of ships is relatively small, two alternate maneuvers are offered for accomplishing the desired results, namely -

Landing at few beaches.
Landing at several beaches in echelon, so that all available ships can concentrate successively on each beach.

148. Boats. -

a. The speed with which troops can be put ashore is directly dependent upon the number and type of boats available and the distance of the transports from the various beaches. The scheme of maneuver, therefore, must take these factors into consideration, particularly where there are not enough boats to embark all of the landing force at one time. The timely support of assault echelons and the prompt exploitation of success require reserves in boats immediately available. This limits the number of boats, and consequently the troops and frontages, which can be assigned the initial assault echelons.

b. The frontage of the initial attack will also be limited by the availability of small, fast boats suitable for assault troops. Such boats should be provided for the leading platoons of battalions which are to be landed in assault. (For detailed discussion of landing boats, see Ch. III.)

149. Hostile dispositions. -

a. Beaches strongly organized for defense should be avoided, if possible, in the initial landings. Advantage should be taken of undefended or lightly defended portions of the shore line, even though presenting less favorable landing conditions, in order to outmaneuver the hostile resistance or to gain a position from which flanking artillery or small-arms fire may be brought to assist the landing at more favorable beaches.

b. This type of maneuver may necessitate awaiting favorable weather conditions in order to effect landings at the desired beaches. It should be recognized that such plans embody additional hazards due to probable delays in execution, and the consequent increased danger of interruption of operations by bad weather or submarine attack.

150. Types of landings. -

a. A simultaneous landing may be made on all selected landing beaches, or the landing may be made by echelon.

b. In attacking by echelon, it is generally desirable to land last at the beach, or beaches, where it is planned to make the main effort. This enables the ships which support that landing to continue, without interruption, in support of the advance of the main effort. Plans must be flexible, however, and constant consideration should be given to the advisability of exploiting a landing already successfully executed rather than attempting a new landing against opposition.

c. The time interval between landings, in an attack by echelon, may vary between wide limits. Where there are sufficient boats to carry all of the landing force in one trip and the supporting ships can cover the various landings from the same general locality, this interval may be only a few minutes. The amount of ships' gunfire to be placed on the various beaches, together with the scheme of maneuver on shore, will determine this time interval. Where two or more boat trips and considerable movement of the supporting ships are required, or where it is desired to cause a movement of hostile reserves toward the first landing, several hours may elapse between landings. The danger of being defeated in detail must be guarded against.

d. Landings by echelon should be attempted only when the beaches, or groups of beaches, are separated by such distances that troops landed on one beach will not be endangered by naval gunfire on another beach.

e. A landing by echelon, as in a landing on a single beach, facilitates the concentration of the hostile artillery fires. In connection with such landings, demonstrations should be made to cause a dispersion of the hostile fire. In addition heavy counterbattery fire should be employed to neutralize the enemy batteries.

151. Illustrative diagrams - Scheme of maneuver. -

a. The following figures illustrate diagrammatically the application of the foregoing principles in the formulation of a scheme of maneuver for a landing operation under varying conditions as to number of beaches and form of coast line.

b. The diagrams are intended merely to illustrate general principles under certain conditions. In actual practice, these conditions may be encountered in a variety of forms and in an infinite number of combinations.

c. The broken lines in the diagrams are not necessarily objectives, but indicate simply how the maneuver may develop on shore. The actual location of objectives is dependent upon the contemplated maneuver on shore, the nature of the terrain, speed of landing, and the probable rate of advance.

d. The arrows in the diagrams indicate the direction of the main effort, that is, the direction in which the commander plans to exert the maximum effort in the accomplishment of the particular task in view. This is a general direction only; diverging local maneuvers are often necessary by subordinate commanders, and all local successes should be vigorously exploited.

Figure 3 illustrates a landing and demonstrations, with a possible maneuver on shore, when the terrain, amount of naval gunfire, or hostile dispositions make it desirable to limit the landings to one beach, or to a few adjacent beaches.

This maneuver has the advantage of simplicity in the execution of the movement from ships to shore and permits the concentration of ships in support of the one landing.

This type of landing, however, enables the enemy to concentrate his artillery on the landing, facilitates the employment of hostile reserves, and entails the maximum extension of front after the landing is effected. Heavy counterbattery and interdiction fires should be employed in connection with such landings.

The demonstrations at C and D may be employed with any of the illustrations which follow. Demonstrations, made on the flanks of a landing, are desirable in order to disperse the enemy artillery fire and to confuse the enemy as to the actual point of landing. Reconnaissance of adjacent beaches may be conducted in connection with such demonstrations.

This maneuver is a modification of that shown in figure 3. It illustrates the capture by flanking action of a beach which is strongly defended or difficult of approach from seaward. Initial landings are made at A and B, which have better approaches, are more difficult to defend, or, on account of unfavorable landing conditions, are less strongly held than C. After the capture of C, landings may be continued at that beach, the troops landed at C being used to push the attack in the desired direction.

The landings at A and B may be made simultaneously or by echelon. In the latter case, ships' gunfire is used first to support the landing at A and then at B, or vice versa.

This maneuver may be used in connection with any of the illustrations which follow.

This diagram illustrates a landing on two beaches (A and B) separated to such an extent that the troops will be initially out of supporting distance. The landings at A and B, as in figure 4, may be made simultaneously or by echelon. In the latter case, the first landing is made at A and the second at B in order to facilitate the later support of the main effort. In the event of a success at A, however, consideration should be given to continuing the landing of troops at that point rather than making a new effort at B.

If sufficient boats are not available for embarking the entire landing force at one time, the first trip may be used for the landing at A and the second trip for the landing at B. In this type of maneuver, where a considerable period of time elapses between the various landings, hostile reserves may be deflected toward the first landing and away from the main effort.

Figure 6 illustrates a landing when a number of beaches are available. The main effort may be initially on the flanks and later in the center. Simultaneous landings are made first at A and F, then at B and E, and finally at C and D, the later landings being assisted by fire and movement from troops previously landed.

Modification of this maneuver may be made by starting at one flank and working toward the other, or by making a simultaneous landing at all beaches. In the latter case, a large number of supporting ships would be necessary.

When sufficient boats are available to transport the bulk of the landing force in one trip, permitting short time intervals between the various landings, this general type of maneuver enables a large number of troops to be put ashore in a short period of time. This is particularly advantageous when the defender has large central reserves, necessitating great speed in the execution of the landings and in the development of the operations on shore.

This maneuver illustrates the seizure of terrain in the vicinity of beaches A, B, and C, which later may be used in connection with the main effort at D.

The landings at A, B, and C may be made in accordance with the maneuvers illustrated in the preceding figures. The landing at D may be delayed until enemy forces have been drawn toward A, B, and C, and the advance inland from D may be used to outflank a defensive position such as X-Y.

In some cases, the plan may visualize landing at D only in case the advance from A, B, and C is stopped. This type of maneuver is particularly applicable where there is a naturally strong defensive position, such as X-Y, barring the advance inland from certain beaches which, in consequence, appear to be lightly held. This maneuver presupposes a marked superiority on the part of the attacker.

In the above maneuver only one landing against opposition is contemplated. A limited beachhead is first secured at A. The troops then push on, capture B, and establish the necessary beachhead to permit an unopposed landing there. Troops landed at B then capture C by a similar maneuver.

This type of maneuver is less fatiguing on the landing force than other types of landings at a single beach, in that the troops landing at B and C do not have to march from A. They are however, landed in close proximity to the front lines. The execution of the landing in this maneuver is relatively slow, and it is generally suitable only when two or more boat trips are required, and where some natural obstacle protects the exposed flank, facilitating a rapid advance, from beach to beach.

This figure illustrates a simultaneous landing on a long shore line having favorable landing conditions throughout its entire extent.

This is the simplest type of maneuver to execute on land, as all units are mutually supporting and complicated movements are avoided. A large number of supporting ships is required, however, and the movement from ship to shore, involving the simultaneous landing of a large number of boats under naval gunfire, is extremely difficult to execute.

Where the necessary number of ships is not available to support this type of landing, compartments of the terrain may usually be found which will permit a landing by echelon, as illustrated in the next figure.

In this diagram, the shore line is suitable for landings at practically all points. Inland terrain features form three natural compartments of terrain, as indicated.

The initial landing is made at A. The troops, after landing, push to the left in order to secure the debouchment from the cul-de-sac in that direction and to confuse the enemy as to the direction of the main blow. Landings are then made at B and C, where field artillery is installed. The main effort is later made at D, E, F, and G, assisted by artillery fire from batteries at B and C, and pressure in the direction of the defile between C and D.

Figure 11 illustrates the capture of islands and a peninsula to permit the passage of boats or transports into a large bay or harbor where the main landing is to be conducted.

In the maneuver illustrated, the islands are taken successively and the peninsula is captured by two converging attacks which may be initiated simultaneously or by echelon. If ranges are suitable, field artillery may be installed on the islands to assist subsequent landings.

When preliminary reconnaissances within the harbor are prevented by situations such as shown above, and the enemy is known to be overextended, it may be advantageous to employ reconnaissances in force in connection with the main landing. These reconnaissances in force are landed as a part of the main landing at several points (as E, F, and H) with a view to discovering the enemy's weak points. These weak points are then quickly exploited by large central reserves held offshore in boats for the purpose.

152. General. - The selection of the hour of landing for any particular operation involves careful consideration of the probable effect of light and darkness, as modified by meteorological conditions, air situation, and navigational considerations. The advantages and disadvantages of daylight and darkness may be further modified by the use of smoke and illuminating devices.

153. Surprise. - Against an alert enemy, it is difficult to effect complete surprise, particularly with a large force. The use of darkness in some or all phases of the operation, however, does increase the chance of securing some measure of tactical surprise, and it deprives the defender, to a material degree, of the information necessary for the proper disposal of his forces to meet the attack. Even with the most efficient illuminating devices, it is difficult at night to estimate accurately the strength of the attacker's forces, and generally there will be areas not illuminated and reconnoitered thoroughly, leaving the enemy in a state of doubt. In addition, the information, necessarily obtained at night largely by planes or patrol vessels, must be transmitted to the commander and is subject to delay, error, or loss.

154. Movement of enemy reserves. - During daylight hours the defender, with his extended system of observation and permanent means of communication, can secure more complete and accurate information without delay, permitting the commander of the defensive forces to act with greater promptness and certitude in the movement of reserves. It is much easier in the daytime, however, for the attacker to discover such movements by the defender, and the air attacks and interdiction fires of the attacker will be much more effective. This will render the use of roads for movement of reserves, and the occupation of positions close to the shore, much more hazardous than at night.

155. Air operations. -

a. Granted that the attacker will always have superiority in the air, night attacks are favorable to the defender because it is only in daylight that full advantage can be taken of superiority in the air. This applies particularly to the protection of transports and combat ships. Bombing under cover of darkness is practically impossible to stop, regardless of the numerical superiority of the attacker in the air. A night operation, therefore, involving the anchoring or laying to of transports for several hours, should rarely be attempted in the face of an active enemy air force. Such an operation may be practicable when destroyers or small craft, not so vulnerable to air attack, are used for transporting troops for the initial assault echelons. Transports carrying the main forces may come in after daybreak under protection of the attacker's air force.

b. The possibility of avoiding discovery of the attack force and attacks thereon by enemy aircraft during the approach to the objective should be carefully considered. If arrival at the objective is planned at daybreak, advantage may be taken of the hours of darkness to avoid discovery prior to the landing. This procedure also extends the area that must be searched to seaward by enemy patrols to include the daylight hours preceding the night run of the attack force. Such operations are within the capacity of modern aircraft, however, and must be expected.

c. Consideration should be given to a surprise landing by parachute troops, or troops with portable landing boat equipment transported by patrol planes during the night from a distant base.

d. Effective air support of the landing is seriously handicapped by darkness or poor visibility due to the difficulty of operating aircraft from ships at night and of locating well-concealed targets in the beach defense area.

156. Operations of naval defense forces. - Even though the attacker has control of the sea in the area of operations, such control does not preclude the defender launching night destroyer

attacks, day and night submarine attacks, and mining operations. The presence of one or all of these threats, and the means available to counter them, are factors that must be considered in selecting the hour of landing. These countermeasures are more effective during daylight.

157. Effectiveness of defender's fire. -

a. Darkness materially reduces the effectiveness of the defender's rifle and automatic rifle fire. Machine guns are affected to a less degree, particularly when firing on their final protective lines. Smoke, if properly laid, can produce the same effect as darkness in reducing the effectiveness of the enemy's small-arms fire.

b. Indirect artillery fire is much more effective when observed, particularly in firing at moving targets such as boats, as the fires can be displaced to follow the targets and the rate of fire can be stepped up when the target approaches the area being shelled. The effective delivery of aimed fire from antiboat guns on the beach necessarily requires that the targets be seen from the guns. Insofar as enemy artillery fire is concerned, therefore, night operations favor the attacker. Smoke is not nearly as effective as darkness in preventing terrestrial and aerial observation.

158. Effectiveness of fire from boats. - The effectiveness of the fire from boat guns will be materially reduced by darkness or smoke. If the attacker plans to have a large number of properly armed boats in his leading waves capable of producing a heavy volume of fire, it is probable that darkness or smoke would be more favorable to the defender in the fire fight which will occur just prior to the landing.

159. Effectiveness of ship's gunfire. - Ship's gunfire on the beaches, as well as interdiction and counterbattery, will be much less accurate at night or in smoke and constitutes a greater hazard to friendly troops. Inshore supporting ships accompanying the boats depend, for their greatest effectiveness, upon direct laying on observed targets. Darkness or smoke would prevent the necessary observation for the conduct of such fire and would thus greatly reduce the effectiveness of, or even preclude, one of the most valuable forms of support. If an adequate number of vessels is available to stand close in and support the attack at short ranges, and the depth of water and configuration of the coast line permits, a day landing is almost obligatory.

160. Navigational considerations. - The navigation of ships and the handling of small boats will be greatly facilitated by a daylight operation. On an unfamiliar coast, without thorough reconnaissance and the establishment of navigational aids, there is no assurance that a landing could be made at night on the designated beaches. The establishment of such navigational aids tends to deprive the attacker of the surprise sought in a night operation but they should not be dispensed with where it is important to land at specific points. Where navigational hazards are great, a day landing may be obligatory.

161. Conduct of operations on shore. -

a. Night attacks are extremely difficult to execute and are rarely attempted in land warfare except under special conditions. Even if a night landing is contemplated, the bulk of the force should be landed shortly before or at daybreak so that the troops will have the benefit of light in conducting the operations on shore.

b. If the decision is to make a day landing, the hour fixed should be early enough to allow sufficient daylight for the operations contemplated for the first day.

162. Meteorological conditions. - The following meteorological conditions may influence the hour of landing:

Prevailing winds.
Surf conditions.
Prevalence of fogs or mists.
Direction of the sun.
Phase of the moon.
Tides.

163. Final selection of hour of landing. - It may be seen from the foregoing that the selection of the hour of landing involves consideration of a number of conflicting factors. The weight to be given each of these factors will vary between wide limits according to the type of operation and the conditions existing in the contemplated theater of operations. In general, it may be said that where the enemy has considerable force in the area of operations but where the choice of landing places is so wide that he cannot defend them all a night landing will probably offer the best chance of success. Conversely, should the choice of landing places be so restricted that the enemy, though deficient in total strength in the area, has been able to establish defenses at each, the best way of overcoming those defenses will be an accurately coordinated day landing, carried out with the support of intense naval gunfire and vigorous air operations against ground targets.

164. Flexibility in planning. - In addition to a preferred plan for the contemplated operation, one or more alternate plans should be prepared prior to embarkation. The organization, equipment, training, and embarkation of the Fleet Marine Force and certain other naval task groups should permit the execution of any one of the prepared plans, a modification thereof, or the preparation and execution of an entirely new plan. Weather conditions, additional information, enemy action, or other changes in the situation which may occur between departure and arrival at destination may require extensive modification of plans, or a complete change of plans, in order to accomplish the mission of the expedition.

165. Basic orders and instructions. - A large part of the orders, instructions, and other matter which must be published prior to embarkation are applicable to any plan which might be adopted in the proposed theater of operations. This includes such orders as those relative to embarkation and movement overseas, basic task organization, intelligence data, basic communication instructions, basic supply and administrative provisions, general instructions to beach and shore parties, armament and equipment of boats, and general instructions relative to indoctrination and methods of landing. Such basic orders and instructions should be published separately, rather than as a part of any one plan, since they remain effective, unless specifically modified, for any plan which may be adopted. Any particular operation plan can thus be limited to those details which are peculiar to that operation, permitting orders and annexes for each plan to be prepared in more concise form. This procedure will be of particular advantage when it becomes necessary to make extensive modification of plans, or to prepare and execute a new plan.

166. Maps and overlays. - A liberal use of maps, overlays, and sketches as part of plans and orders is desirable where such plans and orders can thereby be prepared in more clear and concise form.

167. Dissemination of orders en route. - As far as practicable, all plans and orders are distributed prior to sailing from the last port of call. Necessity will probably arise for the distribution of data secured or prepared after departure, such as airplane photographs, intelligence data, or more detailed instructions. Such data as well as extensive modification of plans or change of plans must be distributed to ships concerned by airplane drop, dispatch vessel, or by rendezvous of some or all of the fleet units concerned. Minor modification of plans may be disseminated by signal communication.

168. Centralization in planning. - The wide dispersion of troops on transports, the difficulties in the transmission of papers after departure, and the time needed for the preparation of orders by intermediate commanders may justify centralization of planning and variation from the normal form and procedure in the issuance of operation orders. For example, in a force consisting of several brigades, force orders may be formulated in sufficient detail to be issued direct to regiments or battalions, thereby obviating the necessity for, or limiting the scope of, brigade and regimental orders for the landing and initial operations ashore. Similarly, certain annexes, such as the Landing Schedule, Naval Gunfire Support Annex, etc., may be published in a form suitable for issue to battalions, either direct or attached to the orders of intermediate commanders.

169. Detailed plans. - Details relative to the preparation of the various operation orders and annexes are covered in succeeding chapters.

201. The attack force. -

a. The attack force is a task organization of the fleet especially constituted for the conduct of landing operations. It consists of -

The naval task groups.
The landing force.

b. If separate operations are contemplated in localities at such distances from each other that direct command and coordination by one commander would be difficult or impracticable, two or more attack forces may be organized.

c. Each attack force is designated by a suitable name, such as "Dewey Attack Force." For reasons of secrecy and to prevent confusion in case the attack force operates in more than one area, it is inadvisable to designate an attack force by the name of its objective or the locality in which it is to operate.

d. The commander and the units of each attack force should be designated at the earliest practicable date. The attack force commander will usually be the senior naval commander of the units of the fleet comprising the attack force. It may be impracticable, however, to determine the complete organization of the attack force until the situation in the proposed theater of operations has been ascertained. Under such conditions, in order to provide continuity of planning and execution, it will be desirable to designate as attack force commander an officer, not necessarily commanding a fleet unit, especially selected for the conduct of the operation, and provided with an adequate staff and a suitable flagship. He should be senior to commanders of fleet units which may be assigned to the attack force. Provision must be made in advance for continuity of command within the landing area during the course of the operation.

e. In order that the attack force commander may better control the operation of all task groups, it is desirable that his flagship operate independently of these groups. If the fire of the flagship is required it is desirable that it be utilized in general support of the operation as a whole rather than to support a specific organization of the landing force.

f. When an advance force (ch. I, sec. III) has been operating in the theater of operations prior to the arrival of the attack force, it is desirable that vessels of the advance force be assigned to the attack force upon its arrival in the theater, so that the operations of the two forces may be closely coordinated.

202. Tasks of naval task groups and landing force. - The normal tasks of the naval task groups and the landing forces are:

a. Naval task groups. -

To provide adequate reconnaissance.

To provide protection against enemy naval forces during the landing operation.

To provide, man, equip and operate the small craft required for the operation, and to land personnel and matériel of the landing force in accordance with the approved plan for the landing.

To support the operation by gunfire, aircraft, and screening operations, fire from boat guns, mine sweeping, and removing underwater obstacles.

To provide signal communication between ships and shore.

b. The landing force. -

To provide troops for reconnaissance of the beach.

To deliver fire from its own weapons while embarked in boats for landing and to assist in manning designated boat guns.

To conduct operations on shore necessary for the accomplishment of the mission.

203. Organization of the naval task groups. -

a. The vessels assigned the attack force are organized into task groups appropriate for the various operations involved and the scheme of maneuver decided upon. These task groups will include some or all of the following:

1. The reconnaissance group, or groups, consisting of vessels assigned the task of reconnoitering the landing area selected for the operation, and such other areas as may be considered desirable in order to confuse the enemy as to the point of landing. The reconnaissance group is generally composed of suitable vessels from the other task groups listed below.

2. The fire support group, or groups, consisting of vessels assigned gunfire missions in support of the landing and subsequent operations.

3. The air group, consisting of aircraft assigned to support the operations. Aircraft of the landing force may be attached to the air group during such periods as may be desirable.

4. The transport group, or groups, consisting of the transports and supply vessels used in carrying troops, equipment, and supplies.

5. The control group, consisting of vessels designated to guide and assist the movement from ship to shore, provide communication facilities with the boats and troops while en route to the beach, and to assist in controlling the supporting naval gunfire. Certain vessels of this group may be utilized at convenient times to lay smoke screens, assist in furnishing fire support, etc.

6. The antisubmarine group, consisting of the vessels designated to protect the units of the attack force from enemy submarines. This group may be given the task of laying destroyer smoke screens to protect vessels and boats from observation. As a rule, this is not a separate task group. Suitable vessels for antisubmarine screen are usually assigned the principal task groups of the attack force.

7. The mine group, consisting of the vessels assigned the task of conducting sweeping and mine-laying operations. This group may be given the task of removing underwater obstacles.

<8. The screening group, consisting of that part of the force assigned the task of providing security from enemy forces afloat.

9. The salvage group, consisting of such light craft as may be available for rescuing personnel of distressed boats, hauling off grounded boats, and the recovery of sunken equipment. (See ch. IV, sec. VIII.)

10. The demonstration group, or groups, consisting of the vessels assigned the task of making demonstrations outside of the designated landing area.

b. It may be necessary to organize a special task group to protect small boats from enemy light surface craft. If a separate group is not organized, this task should be assigned other groups operating in the vicinity of the beaches and routes of approach thereto.

c. Supply vessels carrying boats, crated or knocked-down aircraft, or other equipment essential for the conduct of the landing and hospital ships, may be assigned to the transport group or they may be organized into separate task groups of the attack force. Vessels carrying troops, equipment, or supplies not needed immediately may be organized into a separate task group and kept out of the landing area until required.

d. It may be desirable to assign the tasks specified for two or more of the groups listed in this paragraph to a single task organization. As the operations progress, the composition of the task groups may be changed, certain vessels being transferred from one group to another.

204. The attack group. -

a. When the attack force is to conduct operations on a broad front under conditions which would make direct control by one commander difficult or when the

operation naturally divides itself into distinct tasks, it may be advisable to organize the attack force into two or more attack groups.

b. The attack group consists of a detachment of the landing force and some or all of the naval task groups listed in paragraph 203. Certain of the task groups, such as the air group, reconnaissance group, and the screening group, may be retained under the direct control of the attack force commander and support the operations of all attack groups.

Each attack group is given an appropriate name such as "Right Flank Attack Group, Dupont Attack Force."

205. The landing force. -

a.

1. The provisions of this publication contemplate that the major part of the landing force will be composed of units of the Fleet Marine Force.

2. The Fleet Marine Force is composed of three main elements, namely:

Lightly equipped units suitable for offensive landing operations.
Base defense artillery.
Aircraft.

3. In order to reduce the number of transports in the initial movement it may be advisable to organize a separate transport group for base defense artillery, or certain portions thereof not required until the base is taken. More economical loading of transports will result, however, if base defense artillery is distributed among the vessels transporting the entire force.

4. The employment of the aircraft of the landing force will depend upon the availability of landing fields in the vicinity of the contemplated landing area, and the number and type of vessels available for its transportation to the theater of operations. (See ch. VI, Aviation.)

b. Organization of the landing force. -

1. For operations on shore, the task organizations of the landing force are its regularly organized tactical units such as battalions, regiments, and brigades. Special task organizations are required for -

The embarkation.
The movement from ship to shore.

2. For embarkation the landing force is subdivided into "embarkation groups," each group usually composed of a proportional part of all arms and capable of independent action. Each embarkation group should be embarked in a transport division of the transport group. (See par. 920.)

3. For the movement from ship to shore the landing force is subdivided into "landing groups," each composed of a reinforced infantry battalion, or other unit of approximately the same size. The boats which transport the landing group to the beach are organized into a "boat group." (See pars. 403 to 405.)

c. Embarkation of commanders. -

1. During the preparation of all plans the commander of the landing force, or at least appropriate members of his staff, should be available to the commander of the attack force.

2. For the voyage overseas the commander of the landing force shall, if practicable, be embarked on the flagship of the attack force commander. Provision must be made for the landing of the commander of the landing force and his staff at the proper time.

3. When operating as part of a larger force, commanders of lesser units such as regiments, brigades, or divisions should be embarked on the flagship of the transport division or squadron transporting the units of their commands. During the movement from ship to shore it may be desirable for regimental, brigade, or division commanders or such members of their respective staffs as they may designate, to transfer temporarily to vessels of the control group.

206. The transport group. -

a. The transport group commander is responsible for -

Preparation and assembly of transports, boats, and special equipment for the landing, and the assembly and training of the necessary naval personnel for the operation of these vessels, boats, and equipment.

Assignment of boats to transports, and if necessary, the organization of boats into boat groups.

Embarkation of troops and matériel in accordance with approved plans.

Conduct of the transport group in the movement overseas.

Debarkation of troops and matériel in accordance with the approved plans for the operation.

Designation of boat rendezvous area, or areas.

b. In an operation involving a large number of transports, effective control of the embarkation, movement overseas, and the landing requires that the transport group be organized into

appropriate transport divisions, each embarking a self-sustaining unit of the landing force known as the "embarkation group."

c. The transport group commander operates through his transport division commanders and they, in turn, operate through the transport commanders. The landing force has a corresponding chain of command, namely: (1) The commander of the landing force, (2) a commanding officer of each embarkation group embarked on a transport division, and (3) the commanding officer of troops on each transports parallel chain of command decentralizes and simplifies the planning and execution of the various operations involved. It also permits the closest liaison between corresponding troop and transport commanders.

d. The transport group, the transport division, and the transport commanders should be designated at the earliest possible date and should be free to supervise the preparation of their vessels, training of personnel, assembly of the necessary boats and matériel, and preparation of detailed plans for the various operations. The transport group commander, in particular, should be provided with an adequate staff. Frequent conferences between transport commanders and appropriate commanding officers of units to be embarked are essential during the period of preparations.

e. The detailed organization of transport divisions and corresponding embarkation groups of the landing force is covered in paragraph 920.

f. The transport group commander keeps the commander attack force informed of the progress of the debarkation and advises him when the leading waves are embarked in boats. (See par. 405e, for control of debarkations by transport commanders.)

g. The detailed planning of the movement from ship to shore, see chapter IV.

207. Organization of boats. - In order to control effectively the movement from ship to shore the landing boats are organized into boat divisions, groups, and, if necessary, flotillas, and appropriate commanders designated. (See par. 405.)

208. The control group. -

a. Tasks. - The following are the normal tasks of the control group:

Mark control points necessary for regulating the movement from ship to shore, and other points designated by the attack force commander. (See ch. II, sec. III, Station and Maneuver Areas.)

Control the movement of all boats between the rendezvous areas and the beach. (See pars. 427 and 431.)

Keep attack force commander, and such other commanders as may be designated, informed of the progress of the movement from ship to shore, the landing of various waves, and the subsequent operations on shore visible from seaward.

Assist in control of naval gunfire supporting the landing.

Relay messages from and to the landing beaches.

b. Composition. -

1. If available, the control group should consist of sufficient vessels or small craft to permit one vessel to be assigned to each leading boat group. It may be practicable to utilize as control vessels the fire support ships accompanying the boats, and vessels of the mine group. If sufficient vessels are not available to permit the assignment of one control vessel to each leading boat group, motorboats may be utilized.

2. As the control group must be familiar with the landing area it is desirable that vessels and personnel taking part in the preliminary reconnaissances be assigned to it.

c. Communication. -

1. Each control vessel should be prepared to communicate direct with the landing boats, as well as the flagship of the attack force, fire support groups, control group, and other designated vessels. This will usually require additional communication facilities on each control vessel. (See pars. 711 and 712, Communications.)

2. It is particularly important that control vessels communicate to higher commanders and fire support groups when leading waves pass control points and the line of departure.

3. Visual and messenger boat communication should be established with the beach party as soon as it has landed. Special observers should be detailed to watch for pyrotechnic signals from the boats, aircraft, and landing force.

d. Control of movement from ships to shore. -

1. After marking or identifying the line of departure and control points (see 221 and 222) the designated vessels of the control group rendezvous with the boat groups at the designated time and place, guide them in to the line of departure, and regulate the speed of the movement so that the successive waves will cross the line at the scheduled times. This will permit orders modifying the plan to be transmitted to the boat groups through the proper control vessels. These scheduled times may be previously prescribed by the attack force commander; if not, an approach schedule computed by

the commander of the transport which carried the troops to be guided should be delivered to the control vessel in the boat rendezvous area. As it is extremely important that the boats move on the prescribed approach schedule, it is desirable that control vessels be equipped with long-base range finders with which they can take frequent ranges on the line of departure and beach.

2. If vessels of the control group have the additional task of furnishing gunfire support, they proceed to their prescribed firing stations as soon as the necessity of controlling the boat movement ceases.

3. It is desirable, whenever practicable, that the approach from the boat rendezvous areas to the line of departure be planned as a simultaneous guided movement of all control vessels, each acting as guide to a boat group. See 431 and 432.)

4. After leading boat groups have landed, certain designated control vessels may be utilized as a rendezvous for boats transporting field artillery and reserves. This will permit final orders as to time and place of landing of artillery and reserves to be transmitted through a control vessel.

5. If the transport group is compelled to put to sea for any reason, control vessels may be designated as mother ships for the boat groups until the boats and transports are reassembled.

e. Control of naval gunfire. -

1. The vessels of the control group signal the fire support groups when the leading boats are in the positions prescribed by the attack force commander for opening, lifting, or ceasing fire. (See par. 228f.)

2. In order to assist in the control of fire, spotters from the firing ships may be put aboard control vessels.

f. When two or more boat groups land simultaneously on contiguous beaches, one of the control vessels should be designated to signal all of the necessary information to the attack force commander and appropriate fire support vessels.

209. The reconnaissance group. -

a. In the operation of the reconnaissance group particular attention should be paid to the following:

Identifying "fixes" on the beach and establishing such other aids to navigation as may be necessary. Photographs and panoramic sketches executed by surface craft or submarines, and oblique aerial photographs from seaward will be of great assistance to boat group commanders in locating their beaches, to troop commanders in planning their operations on shore, and to fire support groups in planning and executing the supporting fires.

Ascertaining enemy naval dispositions within and in the vicinity of the landing area.

Determining the suitability of beaches and sea areas required for the conduct of the operation.

Locating underwater obstacles and other obstructions such as booms and nets installed by the enemy, particularly in the vicinity of the selected landing beaches, or approaches thereto.

Ascertaining if beaches have been gassed. This is particularly important on small islands or in other restricted areas.

Locating mined areas.

Ascertaining enemy dispositions on shore and selecting suitable targets, landmarks, and aiming points for fire support ships.

Securing information regarding the enemy air force.

b. For conducting reconnaissance patrols, see chapter IV, section VI.

210. The mine group. -

a. Sweeping operations may be conducted in connection with the preliminary reconnaissance of the landing area, and part or all of the mine group may be assigned the reconnaissance group for this purpose.

b. In the conduct of mine-sweeping operations particular attention should be paid to the transport and fire-support areas, and approaches thereto.

c. Booms, nets, and other obstructions installed by the enemy may be removed by dragging the obstacles into deeper water, wire-cutting parties, explosives, or utilizing boats or small craft to cut breaches.

211. The fire support group. -For detailed tasks and organization of the fire support groups, see chapter V, Naval Gunfire.

212. Shore Party. -

a. The shore party is a special task organization formed for the purpose of facilitating the landing and movement off the beach of troops and material. It comprises elements of both the naval forces and the landing force, and is commanded by an officer of the landing force known as the shore party commander. Each shore party commander is responsible to the senior troop commander operating in the zone which his shore party serves. He exercises control of all activities in the immediate beach area delimited by the senior troop commander in that zone. The beachmaster is the naval officer in charge of the naval section of the shore party. He will act as assistant to the shore party commander and will be his advisor on naval matters.

The tasks of the shore party are as follows:

1. Mark hazards to navigation in the vicinity of the beach and determine most suitable landing points.
2. Effect emergency boat repairs.
3. Evacuate casualties to ships in accordance with Naval Attack Force and Landing Force Medical Plans.
4. Control boat traffic in the vicinity of the beach.
5. Direct landing, retraction, and salvage of boats.
6. Mark landing beach limits.
7. Establish and mark unloading points on landing beaches.
8. Unload the material of the Landing Force from small craft.
9. Remove underwater and beach obstructions.
10. Evacuate prisoners of war to ships in accordance with Landing Force Instructions.
11. Construct landing facilities when required.
12. Maintain liaison with senior troop commander within the zone served by that particular shore party; and in the case of the Senior Shore Party Commander, with the senior command of the landing force ashore.
13. Maintain order and direct traffic on and in the vicinity of the beach.
14. Provide bivouac, parking, and storage areas on and in the vicinity of the beach for various elements using that beach.
15. Insure rapid movement of equipment and supplies landed on the beach, in accordance with requirements of the units which the Shore Party is serving.
16. Maintain a record showing organizations, matériel, and supplies by appropriate categories, which have been landed on the beach.
17. Construct and maintain beach exit routes.
18. Provide for decontamination of gassed areas on the beach.
19. Maintain a situation map for information of landing units.
20. Operate emergency motor maintenance service to assist vehicles damaged in landing.
21. Provide local security for beach area.
22. Perform such other functions as are assigned.
23. Establish communication with adjacent shore parties.
24. Maintain communications with naval vessels and forces ashore as necessary.

The execution of tasks (1) through (5) are functions of the naval component of the shore party for which the beachmaster is directly responsible to the senior naval officer afloat and will deal directly with him in regard to these tasks. Tasks (6) through (22) will be performed by the military component of the shore party. Tasks (23) and (24) will be performed jointly by the military and naval sections.

b. Composition. - The size and composition of the shore party will of necessity vary with the tactical situation. It should embody personnel qualified for discharge of the following functions:

1. Communications.
2. Military Police.
3. Labor.
4. Mess.
5. Liaison.
6. Salvage.
7. Engineer.
8. Medical.
9. Boat repair.
10. Local defense.

213. Landing the Shore Party. - It is essential that the several shore party commanders, along with the shore party, hydrographic reconnaissance, and beach marking personnel, land in the leading boat group, and that the remainder of the shore party be transported ashore as soon thereafter as practicable in order that the full utility of the organization may be developed early in the operation.

214. Medical Service. -

a. Medical units of the landing force are responsible for the treatment, care and evacuation of casualties ashore and for designation of casualties to be evacuated to hospital ships or transports. Landing force medical units are also responsible for movement of evacuable casualties to the beach.

b. The shore party is responsible for placing evacuable casualties in ambulance boats and for regulating the flow of casualties to transports and hospital ships. Ambulance boats along with attendant medical personnel will be furnished by hospital ships or transports as directed in the Naval Attack Force Medical Plan. Upon reporting to the shore party commander initially, these boats are under his control until dispatched with casualties.

c. Details of the medical service afloat and ashore are covered in Chapter IX, Section VIII.

215. Personnel for Shore Parties. -

a. Shore parties should be organized operating units in the same sense as are tactical units of the landing force. They should be composed to fit the specific tactical situation in hand, and should be exercised prior to active operations.

b. The military components of the shore party should be of such composition as to permit the effective discharge of their tasks as listed in 212a above.

c. The naval section of the shore party should be provided from vessels of the transport division in which the military elements of that shore party are embarked. It should include personnel and equipment for discharge of tasks in accordance with paragraph 212a above.

d. The number of shore parties required and their precise composition will vary with the size of the landing force, and the character and number of beaches utilized. As a general principle, one shore party should be organized for each reinforced regiment and this shore party should be susceptible to division in to three parts, each for the support of a reinforced battalion.

216. Reconstruction and relief of Shore Parties. -

a. Following the initial assault phases of an operation, it will frequently be found that only certain beaches are maintained for continued use. In those cases, individual shore parties so released may be used for reinforcement of details on active beaches.

b. Upon completion of the initial transport unloading task and seizure or construction of landing facilities, shore parties should be supplanted by base logistical agencies as the situation dictates.

217. Deleted.

218. Deleted.

219. Assignment of areas. - The various naval task groups must be assigned appropriate station and maneuver areas within the landing area to permit them to carry out their assigned tasks. These will include the following:

One or more transport areas in which transports or other vessels disembark troops and matériel.

One or more fire support areas in which the fire support groups will operate.

Such other stations, or cruising directions, as may be necessary to coordinate the naval operations within the landing area.

220. Transport and gunfire support areas. -

a. Movement of boats. - The transport areas and gunfire support areas must be so located in relation to each other that boats transporting troops and matériel from ship to shore will not be interfered with by the movement of the firing ships, and vice versa.

b. Fire support areas. - There may be several fire support areas, according to the number of supporting ships, the fire missions, and the hydrography and topography of the landing area.

The location of fire support areas, as regards the most effective delivery of the various classes of fire, is covered in detail in Chapter V, Naval Gunfire.

c. Transport areas. -

1. The transport areas should be conveniently located in respect to the landing beaches, and as close inshore as enemy artillery fire and depth of water will permit.

2. The areas selected should, insofar as the hydrography of the landing area permits, afford smooth water for debarkation of troops and matériel, and protection against attack by enemy surface craft and submarines.

3. Where beaches are separated by considerable distances it may be desirable to designate two or more transport areas.

4. The location of the transport areas and the initial movement of boats should not disclose to the enemy early information as to the exact point of landing.

5. Ships within transport areas should not be crowded, as space must be provided for the assembly and movement of boats. In the assignment of berths to transports the intermingling or crossing of boat units should be avoided.

6. Provision should be made for maneuvering the transport group after the debarkation of troops is completed. This will reduce the effectiveness of enemy submarines and aircraft attacks.

7. As soon as the situation permits, transports should move as close to the landing beaches as possible, in order to speed up the landing of equipment and supplies. Smooth water is extremely desirable.

d. Mines. -In locating transport and fire support areas consideration should be given to the probable location of enemy mine fields. Where selected areas are found to be mined they should be swept, or other areas designated.

221. Line of departure. -

a. The line of departure is a coordinating line suitably marked to assist the various waves to land on designated beaches at the proper time, and to coordinate naval gunfire and aircraft operations with the movement of the boats.

b. During daylight, unless prevented by reefs or other navigational hazards inshore of the line of departure, boats deploy into their attack formations on or before crossing the line of departure. In order to insure that this deployment will take place prior to the boats coming under effective small arms or light artillery fire, the line of departure should be from 2,500 to 5,000 yards from the beach. The line should be so oriented in relation to the landing beach that boats will, if possible, have straight run for the beach and the waves will be on proper line of bearing.

c. In order that boats may land on schedule it is essential that the line of departure be accurately located at the prescribed distance from the beach.

d. A separate line of departure should be designated for each beach except where beaches are continuous, then one line of departure may suffice for two or more beaches.

222. Reference and control points. -

a. Reference points. - For reasons of secrecy and to simplify the preparation of plans and orders, it will be found convenient to designate reference points for prescribing the limits of transport areas, fire support areas, lines of departure, etc. Each reference point is designated by a letter and is fixed by giving its bearing and distance from a known point, grid coordinates, or the latitude and longitude.

b. Control points. -

1. Control points are those reference points which are marked by buoys, boats, or small craft for use as aids to navigation for the vessels and boats of the attack force. Control points should be established as follows:

To indicate lines of departure.
To indicate where boats change direction, pass through lanes between fire support groups, and at other points which will aid the control group in regulating the movement of the boats. It is desirable that a control point be located in the vicinity of the point where leading boats should be when the final bombardment of the immediate beach defenses starts.
o aid the various supporting groups to move into the landing area, take accurate station therein, and conduct the necessary operations in the area on the prescribed time schedule.

2. A control point may be established as the initial point for regulating and coordinating the movement of the various naval task groups into the landing area. As an aid to navigation, and to insure effective control, it may be desirable to establish the initial point at a considerable distance to sea.

3. Marking vessels must take accurate station on the designated control points. If the depth of the water permits, it will be advisable, as a preliminary measure, to anchor at certain

control points buoys which are not visible from shore. Small craft, or boats with mast stepped, may be stationed at the buoys at the proper time to insure their being picked up by boats or vessels not familiar with the landing area. This procedure is particularly important in the case of the line of departure, in order that the enemy will not be forewarned as to the exact point of landing. Where the line of departure is close inshore it may be undesirable to put down buoys. In this case, the control vessel may signal the leading boat group when the line of departure is reached.

4. Marking vessels should fly identifying flags by day and show a light to seaward by night. Provision should be made for marking vessels at the initial point and at certain control points within the landing area to dispatch radio signals which may be readily identified when picked up by homing loops.

c. Table of reference and control points. - A table of reference and control points is usually issued as an annex to operation plans and orders. The table may be typed on a diagram showing the various station and maneuver areas, and indicated in figure 1.

223. Illustrative diagram. -

a. Figure 1 shows how transport and fire support areas might be located for landings by echelon on beaches C, B, and A. The initial landing is made at beaches C and B, and then at A. The boats from transport area No. 2 proceed toward beach D and turn near control point EASY for a straight run for beaches C and B. In order to still further confuse the enemy the leading boats may constitute a demonstration and continue on toward beach D. As the landing is by echelon the transports in transport area No. 1 arrive later than those in area No. 2 and the boats from transport area No. 1 have a straight run for beach A.

b. Ships in fire support area No. 3 support the landing at beach C. Ships in fire support area No. 2 support the landing at beach B, and later at A. Fire support groups 4 and 1 are assigned counterbattery, interdiction, and fires on targets of opportunity north and south, respectively, of the line SS', but may reinforce the fires on the beaches with guns not engaged in their primary tasks.

c. Control points HYPO HOW, JIG, PREP PETER, and QUEEN mark the lines of departure. Control points EASY and MIKE provide additional coordinating points for the movement of the boats and, at the same time, are so located as to aid the transport and fire support groups to take accurate station. Control point TARE is the initial point for regulating the movement into the landing area.

224. H-hour and D-day. -

a. When plans or orders are prepared for an operation that is to take place at an hour and on a date as yet undetermined, or concerning which secrecy is essential, the expressions H-hour and D-day are used to indicate that the hour and date of the operations are to be announced in subsequent orders.

b. There is but one H-hour and D-day for all units participating in a given operation. It is usually the time of the initial landing in the main operation. The time of all other landings, movements, debarkation schedules, fire schedules, etc., are indicated as occurring a definite number of hours, minutes, or days before or after H-hour D-day, as explained in detail below.

c. An attack force may plan two or more consecutive operations when the situation is so uncertain as to make it impracticable to base all operations on the same H-hour and D-day. Under these conditions, each operation, or the force conducting it, should be so designated that there will be no chance of a misunderstanding when H-hour and D-day are designated for a particular operation.

d. Hours prior to and after H-hour are indicted thus: "H minus 15 minutes," indicating 15 minutes before H-hour; "H plus 2 hours and 10 minutes," indicating 2 hours and 10 minutes after H-hour.

e. Dates prior to and after D-day are indicated thus: "D minus-1 day," indicating the calendar day prior to D-day; "D plus 3 days," indicating the third calendar day after D-day. Each day comprises the 24 hours from midnight to midnight.

f. Nights are indicated thus: "The night D-minus w days - D minus 1 day," indicating, if D-day were 14 September, the night 12-13 September.

g. When designating an hour that is referred to H-hour as a basis, the time indicated may not be included in D-day. Thus assuming H-hour to be 0800, H minus 14 hours is 1800 the preceding day. When it is not necessary to refer to H-hour as a basis times may be indicated as "0600 D minus 1 day," or "on D minus 4 days at a time to be indicated later."

225. Occupation of the landing area. - The time of arrival of the naval task groups in the landing area should be so regulated as to insure that vessels and aircraft will not be required to arrive within the area until needed. This will minimize the danger of attack by enemy submarines and aircraft, increases the chance of surprise, permits a greater utilization of vessels and planes on missions outside the landing area, and provides the maximum use of the cruising radius of planes.

226. Determination of time factors. - In order to meet the foregoing conditions it is essential that the initial point and other control points be accurately located and adequately marked, and that the time required for executing the various operations be known within close limits. It is particularly important that the time required for lowering and loading boats and the speed of the boats under various conditions of weather and sea should be determined by actual experience.

227. Operations schedule. -

a. An operations schedule, as shown in Figure 2, provides a convenient form for prescribing the sequence of the various phases of the operations and the hour of their execution. The operation schedule provides for a high degree of flexibility to meet unforeseen contingencies. It will be noted that certain important phases are executed only on order to the attack force commander, and that H-hour may be changed to meet existing conditions.

b.

1. The interval between H-hour and the time to start lowering boats should be obtained from the transport group commander. This time interval should be based on the normal weather conditions in the contemplated landing area at the hours under consideration. Modification may be necessary when the state of the weather and sea on D-day has been ascertained.

2. Where boats are to be furnished by ships other than the transport group the schedules must provide that such ships arrive in sufficient time to furnish boats as required.

c. The position of the convoy at dawn and nightfall on D minus 1 day should be fixed at the greatest practicable distance from the landing area, in order to reduce the risk of discovery by enemy aerial patrols during D minus 1 day.

228. Decision as to H-hour. -

a. In order to plan the preliminary movements of the various task groups it will be necessary to decide upon a tentative D-day and H-hour some time in advance. It is desirable to postpone making a final decision as to the exact H-hour until the attack force commander has had opportunity to ascertain the progress of the various operations and movements and evaluate the influence of the weather and other factors.

b. Care must be taken to announce the definite H-hour sufficiently in advance to insure its dissemination to all concerned in time for the various task groups to issue final instructions and take proper station.

c. By the time the transport group arrives in the transport area, and probably before, the attack force commander should have sufficient information on the weather and operations of the various task groups to decide definitely upon H-hour. It should be based on (1) the hour transports can actually start lowering boats, and (2) the data furnished by the transport group commander as to the debarkation interval and the running time of boats under existing weather conditions.

d. When H-hour is definitely fixed all time schedules based on H-hour are transcribed into actual times.

e. All task groups must make every effort to maintain the prescribed schedule and should report their progress periodically or at prescribed hours. They must be prepared to make the necessary adjustments in their operations in case of a change of H-hour at any time. It is extremely undesirable, however, to change H-hour after boats are in the water, and it should only be done in case weather conditions or enemy action makes it impossible to carry out the prescribed schedule within reasonable limits.

f.

1. Short delays occurring during the ship-to-shore movement may be compensated for by making minor adjustments in the hour of landing of certain boat groups, and in the corresponding gunfire schedule. These minor adjustments may be made during the boat movement without announcing a change in H-hour. This method is desirable when boat groups other than the one affected by the change are proceeding on schedule, and the beaches are sufficiently separated to obviate the danger of delayed bombardment on certain beaches falling on friendly troops which have already landed at other beaches.

2. The following example will illustrate how this adjustment may be effected: Assuming a heavy bombardment is to be placed on a beach from H minus 25 minutes to H minus 3 minutes. Running time from line of departure to beach, 10 minutes. H-hour is set for 0800. On passing a control point at 0730 the control vessel estimates the leading wave will land at 0820, 20 minutes late, and immediately transmits this information to the attack force commander and fire support vessels. The control vessel would then regulate the movement so that the leading wave would cross the line of departure at 0810 and land at 0820. The fire support group should be directed to open fire at 0755 and should plan to life the fire 7 minutes after the control vessel signals the line of departure is actually crossed. The time of lifting the fire should be further checked by direct observation from the control vessel and fire support group.

g. Timepieces throughout the attack force must be synchronized.

229. Coordination by event. -

a. The inability of boats, aircraft or of troops on shore to maintain an exact time schedule will be the usual case, and deviation from estimated times must be regarded as normal. It is often desirable that troops push forward as rapidly as possible and not be restrained by previous calculations. Coordination by time is more likely to fail than to succeed. Wherever practicable, coordination should be effected by event which may be done by indicating the arrival of units at a certain point by pyrotechnic or other signal. The signal may be given by the supported unit or by an observer who is in a position to view the movement.

b. The following is an example of such coordination. A landing team approached a beach while gunfire from ships bombarded the beach defenses. When the boats reached the proper distance from the beach, the embarked troop commander fired a red pyrotechnic signal to indicate that ships' gunfire should cease. This signal was repeated by the flagship of the firing group in acknowledgement and also as a signal of execution for planes to drop smoke bombs on the beach. This actual operation succeeded.

230. For coordination of naval gunfire, aviation, and movement of boats see chapter V, section IV, and chapter VI, paragraph 624.

301. Boat requirements. -

a. A primary consideration in a successful landing against opposition is the provision of landing boats in adequate numbers, and with suitable characteristics to land the personnel and matériel of the landing force in accordance with the tactical and administrative plans. Allowance should be made for probable boat losses.

b. Number of boats required. -

1. It is highly desirable that sufficient boats be available to land all combat troops, without the need for any of these troops having to wait for a second trip. The number provided should at least permit the landing in the first trip of the boats of sufficient assault battalions, with essential combat equipment, to cover the required frontage in the proposed operations, together with the necessary artillery and local reserves to hold the ground gained until reinforcements are landed in later trips.

2. Lighters and barges, in addition to the boats used to land troops, must also be provided to land the necessary equipment and supplies of the landing force within the time limit and under the conditions likely to be encountered.

c. Scheme of maneuver. - The number of boats available must be considered in determining the scheme of maneuver to be adopted. A shortage of boats will probably require a reduction in the frontage on which the landing is to be made, and may slow down the advance inland of the leading elements due to the delay in landing reserve echelons. Under these conditions, more time will be available for the enemy to concentrate against troops ashore, as on a series of small islands, the landings can be made successively by using the same boats in each landing.

d. Data on boat requirements. - Data on boat requirements for landing personnel and matériel of all units of the Fleet Marine Force can be obtained from Marine Corps Organization and Tonnage Tables, and from "Logistic Data, U.S. Marine Corps."

302. Transportation of boats. -

a. The transportation of the required number of boats to the theater of operations is a serious problem. The stowage requirements for boats and other deck cargo may be so large that unusual methods of boat stowage may be imperative. Such conditions may require stowage in holds or 'tween deck compartments, or construction of platforms or stages designed to increase the available deck stowage space. Some situations may permit the larger boats and lighters to be towed to the landing area. Specially converted ships to act as boat carriers may be necessary in large operations.

b. Insofar as possible the boats and lighters needed in the landing should be carried on the transports. Each transport on which combat units are embarked should carry, as a minimum, sufficient boats to land one reinforced infantry battalion.

c. The capacity of ships' booms under all conditions of weather likely to be encountered will normally fix the maximum weight of boats which may be carried. Specially designed sectional boats and lighters of large capacity may be carried broken down for assembly after arrival at destination. Where time is available, and on ships with low freeboard, arrangements may be made for carrying lighters, beyond the capacity of the booms, to be launched over the side.

d. When it is impossible to accommodate sufficient boats on the troop transports, it may be desirable to provide one or more specially designed ships to act as boat carriers.

303. Boats for landing assault battalions. -

a. It is extremely important that the assault battalions be landed in suitable boats. Desirable characteristics of such boats are:

1. Armament. - Should mount suitable weapons capable of producing a heavy volume of fire.

2. Speed. - Should be fast. Boats for leading waves should have a speed of not less than 12 knots, a greater speed being desirable.

3. Shallow draft. - Should be able to run well up on any type of beach, override underwater obstacles, and ground on a fairly even keel.

4. Good surfboat. - Should be seaworthy and easily handled in surf.

5. Armor. - Should have armor protection against small-arms fire. This is particularly necessary for coxswain, gunners, engine, and gasoline tank.

6. Rugged. - Not easily damaged by pounding in the surf.

7. Nesting. - It is desirable that the boats be suitable for nesting or stowing in tiers aboard ship.

b. Special type boats such as rubber boats and amphibian tractors should be provided in sufficient numbers for any special missions requiring this type of equipment.

304. Size of boats. -

a. The use of relatively small boats in landing the leading echelons has many advantages. A heavy volume of fire can be developed upon approaching the shore, small boats can be beached closer in, troops are quickly disembarked and deployed for attack on shore, and a number of small boats presents a less concentrated target for enemy fire. Small boats can be nested in large boats aboard ship or stowed in spaces not suitable for larger types, and can be carried on vessels not equipped with large capacity booms.

b. Figure 1 illustrated diagrammatically the advantages of small boats over large boats in landing leading waves.

Company A, on the right, lands its leading waves in eight small shallow-draft boats. The beach is covered by the fire of boat guns from the eight boats. Boats run well in to the beach and troops are on shore with minimum delay. Troops deploy ashore with slight lateral movement. The enemy fire is dispersed over eight targets, and a relatively small number of men are exposed to a single shell, mine, or the beaten zone of a machine gun.

Company B lands its leading wave in one large boat. This boat beaches relatively far out, has little fire power, enemy fire can be concentrated, disembarkation and movement are slow, and troops must move laterally to get into attack formation. For example, the flank squads of Company B would have to debark and move 200 yards directly by the flank under enemy fire before gaining their proper places in the attack formation of the company.

c. Large boats, however, have certain advantages, particularly for rear waves. To land a given number of troops requires fewer boats, less stowage space aboard ship, and fewer boat crews. Large boats simplify and speed the execution of the ship to shore movement, particularly where the beach or approach thereto is restricted. They can be used to best advantage where, due to surprise or under protection of troops already landed, the boats and troops disembarking will not be subjected to aimed fire of small arms or antiboat guns.

d. It will be seen from the foregoing that from tactical considerations, as well as from the standpoint of procurement and transportation overseas, it is desirable that boats of several sizes be made available. The following sizes are the most suitable:

1. Boats with a capacity of from 12 to 20 fully equipped men, in addition to the crew, for landing the leading waves. Sufficient boats of this size should be provided to land from 10 to 15 percent of the infantry of the landing force. Where destroyers are to be utilized for transporting troops and landing boats, it may be desirable to supply boats having a capacity of even less than 12 fully equipped men.

2. Boats with a capacity of 20 to 40 men for landing support echelons, that is, the second waves. Sufficient boats of this size should be provided to land from 10 to 15 percent of the infantry of the landing force.

3. Boats with a capacity of 40 or more men for landing reserve echelons, that is, third and succeeding waves. Sufficient boats of this size should be provided to land from 20 to 25 percent of the infantry of the landing force.

4. When boats are provided in accordance with the above provisions, about one-half of the total number of infantry battalions of the landing force will be equipped with suitable boats to land in assault formations.

305. Speed of boats. - The time that boats are in the water between the transport area and the beach is an important consideration. Fast boats are less vulnerable to enemy fire and reduce the time available to the enemy to concentrate his troops and otherwise perfect his defensive measures. Fast boats in the leading waves decrease the interval between the lifting of the naval supporting fire and the arrival of the boats at the beach. When this naval gunfire lifts, the enemy may be expected to man his defenses near the beach. Any decrease in this interval will materially improve the chances of success of the landing.

306. Boat armament. -

a. In order to compensate for the probable limitations of naval gunfire and the necessity of lifting this gunfire when the leading boats are still well off the beach, each boat of the leading waves should be heavily armed with machine guns, a mortar, or other suitable weapons.

b.

1. Boats in the leading waves should be prepared to place a heavy fire on the enemy defenses near the beach. While the accuracy of this fire may not always be depended upon for destruction of point targets, its volume makes it effective for covering the beach area immediately dangerous to the landing of troops. Fire from boats can be compared with assault fire of troops attacking on land; that is, fire delivered while actually moving forward in the assault, which, while it cannot be considered accurate, has been found efficacious in keeping the enemy down. The fire from boat guns is assault fire delivered under extremely advantageous conditions and is of particular value during the period between the lifting of naval gunfire and the time troops are deployed on shore. After the boat grounds opportunity may develop for well-directed fire on visible targets at short range.

2. Boats in succeeding waves should be prepared to open fire on enemy aircraft and on the beach when an opportunity is presented and such fire does not endanger preceding waves.

c.

1. All guns should be suitably mounted for firing at targets on the beach; machine guns should also be capable of delivering effective all-round antiaircraft fire. Mounts should provide for rapid and accurate laying from a moving platform.

2. It is preferable that boats guns and mounts be part of the fixed installation of landing boats. In this case antiaircraft and other fire is possible when boats are returning from the beach or carrying troops not armed with suitable boat weapons. In the event that boat guns are not otherwise available, the armament of the troops being landed can be so used.

d.

1. The .30-caliber machine gun, due to its rapid fire, and its adaptability for mounting and firing from small boats is an extremely effective weapon. A large percentage of the boats should be so equipped.

2. Mortars are effective because of the large explosive charge of the projectile, and the relatively small dispersion in range of such high-angle weapons due to the pitching of the boat. Properly to mount and fire this weapon from a boat, however, usually requires a serious reduction in troop carrying capacity.

3. Other automatic weapons, such as the .50-caliber machine gun, may be used to advantage, due consideration being given to space required to mount and operate the weapons.

e. Ample ammunition should be carried. While the transportation of ammunition is not the serious problem that it is in land warfare, it must be considered in making up the load of small boats.

f. The effectiveness of the fire from boat guns will vary materially, depending upon the training and experience of the personnel, the type of boat and gun mount used, and the character of the seas. Training of gunners, including actual firing under conditions similar to those to be expected in the operations, is of particular importance.

g. The troops embarked in the boats should be so disposed that they may use some of their weapons, if needed, to augment the fire power of the boat guns against shore targets and aircraft.

307. Draft of boats. - Light-draft boats are particularly desirable for leading echelons. Boats with heavy draft will ground a considerable distance offshore, causing troops to disembark in water above their waists and struggle ashore under severe handicap. This difficulty is accentuated on gently shelving beaches where the boats ground an appreciable distance offshore, and on beaches where the boats ground on a bar with deeper water between the bar and the shore. Troops wading ashore receive limited support by gunfire during this period, movement is slow, equipment is handled with difficulty, and the morale effect is bad. Under such conditions heavy casualties against even slight enemy opposition may be anticipated.

308. Boats for landing reserve battalions. - Boats with large capacity are most desirable for reserve battalions which are landed under the protection of other troops. Where it is necessary to land reserve battalions in the second trip of the boats, the movement can be expedited by embarking the reserves on destroyers or other small craft which are moved as close to the beach as safety permits.

309. Lighters and barges. -

a. Tank lighters. - Self-propelled lighters capable of landing light tanks with or ahead of the leading wave are highly desirable. The lighters should be of shallow draft and should provide for the tanks being run ashore without delay under their own power. The lighter should be heavily armed to provide a point of support on the beach and cover the landing of the tank. These lighters can also be used for the landing of artillery, other vehicles and heavy matériel.

b. Small lighters. - Small lighters with shallow draft and other suitable characteristics may be used to augment the artillery and tank lighters in the landing of matériel.

c. Special barges. - Special barges may be required for the delivery of water, gasoline, and fuel oil in bulk to the beach during the later phase of the landing.

310. Table of characteristics. -

a. The use of standard ships' boats is not contemplated for expeditionary forces. They may, however, be used for ships' landing forces.

b. Characteristics of standard Navy boats are shown in figure 2. The explanation given in the paragraphs which follow should be considered when using the data given in the table.

311. Capacity in boat spaces. -

a. A "boat space" is the space and weight required for one marine with his individual combat equipment. A marine so equipped is assumed to weigh 224 pounds (one-tenth of a long ton) and to occupy 13.5 cubic feet of space.

b. The number of boat spaces available for troops (or matériel) is computed as 60 percent of the rated maximum personnel capacity of the boat, less number of men in the crew.

c. Boats should not be loaded to capacity as shown in column 2 except for simple ferrying operations under ideal sea conditions. It should be further realized that the rated capacities as shown in column 2 will be modified by any of the following exigencies:

1. If the sizes of the boat crews exceed the minimum as shown in column 6, the rated capacities as shown in column 2 must be decreased accordingly.

2. If boats are to come under fire, there should be sufficient room to allow troops to get down low in the boats.

3. If weapons are to be fired from the boats, sufficient boat spaces should be allowed for their operation.

d. It should be noted that the space and weight of any protective armor, boat guns and ammunition, extra anchors, etc., will correspondingly reduce the capacity of a boat.

e. The capacity of a boat in tons is one-tenth of its rated capacity in boat spaces.

312. Speed in knots. - The speeds indicated in column 3 of the table represent average speeds with loaded boats, engines in good order, and fairly smooth water. Speeds will vary and should be determined by actual tests under various conditions of weather, sea, and load. The speed of a boat used in towing is cut approximately 50 percent when the combined load of the boats in tow equals the rated capacity of the towing boat.

313. Time to load. - The loading times in the table are based upon debarking under average conditions and using cargo nets over the side of the transports in place of ladders and gangways. An allowance of about 50 percent has been made for delays which may be expected under war conditions and time for coming alongside. The time of loading a boat will vary according to the relative amount of personnel and matériel comprising the load, the facilities of the transport for discharging, the training of the personnel, and the condition of the sea. The loading time for each boat should, therefore, be determined by tests conducted under various conditions, using the actual load to be transported by the boat.

314. Designating letters. - In boat diagrams and orders relative to debarkation it is convenient to designate each type of boat by a letter, using the designating letters listed in column 5 of the table. For example, the designation "A-1" should be used instead of "50-foot motor launch No. 1." These designating letters should be placed on the boat. (See 421c (9, 10, 11).)

315. Crew. -

a. The figures shown in column 6 of the table indicate the minimum number of men required to handle the boat. The figures do not include boat officers, gunners, additional personnel for handling lines, signalmen, or Hospital Corps men for ambulance boats. Marines to be landed may be used as gunners. (See 411.) Members of the beach party can be detailed to duty as boat officers, linesmen, etc., The number of additional officers and men must be determined for any particular situation and the number of boat spaces shown in column 2 of the table reduced accordingly.

b. The exact strength of the crew and other Navy personnel that will embark in each boat must be determined early, and this information made known to the landing force before the Boat Assignment Tables are initiated. (See 421.)

316. Boat spaces required for matériel. -

a. For general cargo, such as ammunition, rations, camp equipment, etc., the number of boat spaces required can be computed with sufficient accuracy by multiplying the weight of the cargo in long tons by 10.

b. For vehicles, consideration must be given to the weight and dimensions of each article, and the center of gravity of the boat load. The dimensions of vehicles are given in "Logistic Data, U.S. Marine Corps."

317. Armament. - Boats should be armed as indicated in paragraph 306a of this chapter.

318. Armor. - It is desirable that boats to be utilized for landing assault echelons against opposition afford some armor protection against enemy small-arms fire. For this purpose protective plating can be rigged from waterline to gunwale in space occupied by troops, with additional protection for gunner and coxswain. The weight of the plating will decrease the speed and capacity of the boat, and possibly its seaworthiness. These factors must be considered in determining the practicability of installing plating.

319. Equipment for handling motor launches in surf. -

a.

1. Two stern anchors of appropriate type and weight, and sufficient length of line (about 3¹/2 inches in circumference) to span the breakers should be in the boat for use in preventing it being broached while in the surf and to assist in its retraction from the beach. A luff tackle rigged to the towing post may be used to aid in hauling in the anchor line during retraction. The anchor and line should be carried properly faked in the stern ready for letting go.

2. Heavy seas, strong currents or hard bottom will require the holding power of two anchors for each motor launch. In such cases it is preferable that the two anchors be bent in tandem on a single anchor line, with about 10 fathoms of line between anchors. One anchor is usually sufficient for the 26-foot motor whaleboat.

b. Bowline. - A bowline should be coiled down in bow ready to run to the beach.

c. Quarter lines. - Quarter lines are not necessary except in the case of boats which must remain beached in a moderate to heavy surf for an appreciable period; that is, for a longer time than that normally required to unload infantry with light combat equipment.

d. Canvas screens. - Canvas screens lashed tightly to stern railings and supports and secured to stern beading will reduce the amount of water shipped over the stern in case of following seas. Flaps should be fitted in screens to permit working of stern anchor lines and tiller.

e. Engine cover. - If necessary a canvas cover should be rigged over the engine housing to keep the engine dry, care being taken to allow for the intake of air.

f. Oars. - Oars with grommets and hole pins should be provided.

320. Procedure for handling motor launches in surf. -

[See Skill in the Surf - A Landing Boat Manual (LCVP's and LCM(3)'s) for further details.]

a. A surf landing is one of the hardest duties a boat crew is called upon to perform. Special training is necessary for success and each beach must be studied during the approach. The coxswain should give his orders by whistle or voice if the latter can be heard above the surf. The engineer must be alert at all times to give the anchor men as much assistance as possible with the engine. The most dangerous place in the surf is from the crest of the breaking waves to some distance shoreward. The distance of this area from the beach varies with the slope of the beach. On a flat beach waves will break well out from shore and once through this area a boat is in comparatively safe water. On such a beach the stern may strike first when a wave recedes, in which case the propeller has to be stopped to avoid damage. On a steep beach when the stern and propeller are clear, the engine should be used to help maintain the boat squarely on the beach.

b. Upon approaching the beach the first anchor should be dropped about 5 or 6 boat lengths from the line of breakers, and the second as soon as the line between anchors has run out. The boat should be timed to follow directly behind a breaking wave if possible, and the anchor line should be paid out with a slight strain until the boat actually strikes the beach. Anchor men should then hold and secure the anchor line and the bowman should go over with the bow line and hold the bow to the beach. Anchor lines must be kept well taut at this point to insure against broaching. If swells are not parallel to the beach, landings should be made normal to the swell. When landing in a strong cross tide or wind the boat will fall off as it goes in and as a result its anchors will be to windward or against the tide. This is where they should be.

c. The greatest help in making a successful landing is to have well set anchors and a taut anchor line. The boat should be timed to follow directly behind a breaking wave, but once in the surf it should not hesitate but keep going. Anchor line should be paid out, keeping a slight

tension until the moment of striking the beach, then it should be kept well taut to prevent broaching. If the anchor line is properly handled the boat will not broach to.

d. In getting off the beach the bowman should be recalled as soon as the last troops clear the boat. On a flat beach the waves must be watched very closely and when the stern is lifted the anchor men should haul and the engine be backed hard. This is repeated for successive waves. Luff tackle should be used here if necessary. The anchor line must be taut before the next wave hits the stern. On a steep beach the danger is from waves breaking over the stern and swamping the boat. This can be avoided only by getting out fast. Care must be taken not to back over and foul the anchor line. Once through the breakers the anchor line should be taken in by hand.

e. When 26-foot motor whaleboats are headed into choppy seas, as many of the troops as possible should be moved well aft to lighten the bow. A steering rowlock should be installed and a steering oar provided for use in case of a disabled tiller. The same rowlock serves as an excellent fair lead for paying out the anchor line.

f. The procedure herein outlined is intended as general doctrine applicable to handling of powerboats in surf. The normal boat equipment required for the several types of standard Navy boats and detailed instructions to boat crews for landing through various conditions of surf with the least danger to personnel and material have been promulgated in other publications and instructions.

321. Miscellaneous provisions. -

a. Thwarts and bottom boards. - Movable thwarts should be removed. Bottom boards should be removable to permit bailing.

b. Wire cutters. - Wire or bolt cutters, with long handles, and hacksaws should be provided for cutting barbed wire or heavier wire entanglements at beaches and approaches thereto.

c. Cargo nets and assisting lines. - A cargo net on each bow stopped along rail, or lines looped along rail from bow to amidships will be of material assistance in disembarking troops and equipment from large boats.

d. Boat compasses. - The errors of all boat compasses should be accurately determined prior to the landing.

e. Life buoys. - Boats should carry a limited number of life buoys, and life jackets for troops embarked.

f. Signal equipment. - Signal equipment to be carried in boats should be prescribed in appropriate orders. (See ch. VII, Communications.)

g. Protection from chemicals. - Boats should be equipped with protective covering and decontaminating agents for protection against chemical attack. (See par. 831.)

322. Special Navy landing craft. - See confidential pamphlet "Characteristics of British and United States Landing Craft, Landing Ships, Landing Vehicles." [FTP 207]

401. Scope. -

a. The scope of this chapter includes those considerations directly connected with the planning and execution of the movement of troops from the beginning of their debarkation from transports until they are landed on the beach. It deals primarily with the infantry battalion and smaller units, and the corresponding boat organizations. Naval gunfire and the landing of field artillery, tanks, and other arms and services are treated in separate chapters.

b. Although the same principles apply, special adaptations of the methods prescribed herein will be necessary in the event the situation favors towing or ferrying by larger vessels, or landing directly from larger vessels at piers or beaches.

c. In the formations illustrated in this chapter use of the following types of boats is contemplated:

Special Navy landing craft. Standard Navy boats (for ships' landing forces).

d.

1. The formations illustrated in this chapter are, in general, also applicable for rubber landing craft and landing vehicles in the special operations where employment of those types is desirable. Necessary modifications entailed by the differences in capacities and other characteristics of the above types should be made.

2. Rubber craft should be available for use in the following situations:

a.Crossing water too shoal for larger boats.
b. Negotiating underwater obstacles.
c. Landing in rocky and difficult places.
d. Surprise landings.
e. Landing from ships unable to accommodate a sufficient number of larger boats.
f. Landing raiding parties and reconnaissance patrols.
g. Landing from water-borne aircraft - see paragraph 155c and chapter VI.
h. For river crossings after the initial landing.
I. Landing of intelligence agents.

3. Landing vehicles, track, will be useful and should be available for the following employment:

a. Crossing water too shoal for regular landing boats.
b. Crossing coral reefs.
c. Negotiating obstacles both under water and on land.
d. Crossing swampy or marshy areas.

e. Movement of personnel, equipment, and supplies from transports to locations inland without unloading at the beach.

f. In lieu of tractors and trailers in the early phases of an operation before motor transport has been landed.

e. The formations discussed hereafter are not based on any specific tables of organization because of the changes to which such tables are subjected. The illustrations are of a general nature, adapted to three rifle platoons in each company, three rifle companies in each battalion, and three battalions in each regiment, with certain heavier weapons as an integral part of the above echelons. The frontages assigned units on shore are based on an average of one man to each 4 to 8 yards of the firing line, with adequate supports and reserves to assure proper distribution in depth. Unusual conditions, such as night attacks or rough and wooded terrain, may justify deviation from the limits given.

402. Ship to shore movement vital part of attack. -

a. The ship to shore movement of the small boats carrying troops embraces an important phase of the attack itself. The movement is more than a simple ferrying operation and involves much of the tactics of fire and movement. This may be readily realized from a brief review of the basic elements of an infantry attack on land prior to the hand-to-hand conflict.

b. An attack on land opens with preparatory gunfire laid on the defending enemy positions for both destruction and shock. This fire is increased in severity until masked by the assaulting infantry. For ease of control, the infantry begins its distant approach in comparatively large columns, but, as the approach continues and the danger from enemy weapons increases, the infantry, for its own safety and ease of prospective deployment, breaks into smaller units. Finally, in order to reduce losses further and to use effectively its own weapons, it is forced to deploy. Then, when it is judged that the combined fires of the artillery and infantry have produced sufficient effect, or at a time previously ordered, the gunfire lifts and the deployed infantrymen, still maintaining their fire, rush the enemy positions with the bayonet.

c. In the attack on the immediate beach defenses in a landing operation, all of the above phases up to the last rush take place while the attackers are on the water. This indicates that the leading troops must necessarily be broken into small groups as soon as danger from shore weapons becomes acute or the necessity arises for the use of their own weapons. A deployment of small boats is necessary to accomplish this. All lateral maneuvers essential to placing the troops in the proper attack formations and opposite the desired landing place must also take place at or before this time. Finally, the leading troops must be quickly delivered in formation on the beach, deployed as skirmishers, or as near thereto as the small boats will permit. Supports and reserves must be maneuvered on the water so as to exploit successes, and artillery must follow at the proper time and place to enable it to support the attack beyond the initial assault.

d. Landing operations definitely place the burden of an important phase of the initial attack upon coordinated movements of various types of naval craft in accordance with land tactical plans. Thus, the movement from ship to shore should not be regarded as merely a preliminary movement, but as an integral and vital part of the attack itself, demanding of the boat commanders a high order of tactical knowledge and skill and a complete control of the boat formations involved.

403. Major groupings. -

a. The organization of any ship to shore movement of troops is naturally divided into two main categories: (1) The task organizations of the landing force; and (2) those of the small boats in which they are to move and initiate the fight.

b. The task organizations of the landing force consist of various combinations of its regularly organized units (squads, platoons, companies, etc.). These combinations are not only organized

to accomplish limited tasks during the initial landing but also to enable the attack to be continued inland without delay. The task organizations of the small boats should, as far as the number and types of boats permit, conform to those of the landing force, so as to facilitate the landing of troops in the formations which will permit them to carry out their shore missions.

c. The basic task organizations are as follows:

Landing force: The landing groups.
Small boats: The boat groups.

404. The landing group. -

a. The landing group is the basic task organization of the landing force for the movement from ship to shore.

b. In large operations it normally consists of an infantry battalion, plus such artillery, tank, antitank, antiaircraft, medical, and engineer units as may be attached. It also includes all other units attached for landing with it for purposes of organization of activities at the beach for command, and for communications. These latter units usually include shore and beach parties, forward echelons of higher commands, and liaison agencies. (See fig. 1 for one example of the composition of a landing group.)

c. In order to permit the best use of available boats, provide for combined training, and simplify the issuance of orders, all troops to be landed in formation should be organized into landing groups.

d. Each landing group is identified by a number, followed by the name of the principal organization. The senior troop commander in each group is usually designated as its commander.

e.

1. The organization of landing groups is published in the form of a table, as shown in figure 1. It is preferable to issue a consolidated force table showing all landing groups organized in the force. The table should be issued as early as practicable after the composition of the landing force is known, preferably before embarkation of troops, and independent of any tactical orders for a landing. This table may then be used as a basis for assignment of boats, organization of embarkation groups, transport loading, etc.

2. The table should show the number of boat spaces required for each organization and the total for each landing group. Motor vehicles and heavy equipment requiring special boats or landing gear should be listed separately. Infantry battalions which it is planned to use in assault should be so designated, so that suitable boats may be assigned.

3. In the later issuance of tactical orders for a specific operation, the composition of the landing groups may be modified as found necessary to meet the requirements of that particular operation. The assignment of attached units to separate boat divisions, as indicated in figure 1, is therefore desirable.

405. Organization and command of boats. -

a.

1. Due to the fact that the landing groups must be landed in tactical formations, the boats which are to transport them to the beach may, when deployed, be spread over large areas. From figure 2, it will be seen that the boats transporting an assault battalion may occupy an area of some 1,000 by 5,000 yards. In order to control and maneuver boats over such a large area, careful organization, adequate communications, and a proper chain of command are essential. This is provided by the following task organizations:

The boat group.
The boat divisions of the boat group.
The boat flotilla.

2. The boat group. - The boat group is the basic task organization of the boats to be used for transporting troops from ship to shore. One boat group is organized for each landing group to be landed in the first trip of the boats. The boat group is designated by a number, as "Boat Group No. 1," and is commanded by a naval officer known as the "boat group commander."

3. The boat division. - The boat division is a task organization of two or more small boats within the boat group. It transports a platoon, company, or other tactical subdivision of the landing group. (See fig. 2.) During the ship-to-shore movement, the boat division operates as a unit and is maneuvered by the boat division commander. The organization into boat divisions facilitates the control of the boat group as a whole by permitting the boat group commander to exercise command through his boat division commanders rather than dealing directly with individual boats. In order to decentralize and facilitate detailed tactical planning of the operation of small assault units, and to permit a wider choice of formations of the company

and battalion, every effort should be made to organize a separate boat division for each of the assault platoons of the landing group. Each boat division is designated by a number, as "Boat Division 1, Boat Group No. 1."

4. The boat flotilla. - The boat flotilla is a task organization of two or more boat groups. The boat flotilla is organized as such under the following circumstances:

a. To coordinate planning and training when a common commander of two or more boat groups is necessary to advise on the procurement and proper assignment of boats and naval personnel, and to assume charge of indoctrinating and training the boat groups.

b. To facilitate execution when the operation of two or more boat groups in a restricted area demands the actual presence of a common commander.

In either a or b, a flotilla commander is appointed by either the transport group commander or the transport division commander, as appropriate. During operations he is embarked in a fast boat and proceeds so as best to exercise command during the movement from ship to shore.

b. Waves. -

1. A wave consists of the boats within a boat group which carry the troops that are to land approximately simultaneously. It may consist of a single boat division or two or more boat divisions (landing abreast).

2. Boat groups land in successive waves corresponding as nearly as possible to the tactical formation desired for the troops during and after landing. The landing formation of the boat group to meet these troop requirements is controlled by the assignment of boat divisions to waves. The number of waves in a boat group and the composition of each wave may thus vary for different beaches, depending upon the nature and extent of the beach, the approaches thereto, the terrain inland, and the scheme of maneuver of the troops.

3. Waves are designated successively from front to rear as "first wave," "second wave," etc. Owing to the distance which may exist between waves, each wave should have a commander. He will be one of the boat division commanders, except in large waves which should be commanded by a separate officer embarked in a separate boat.

c. Figure 3 is designed to show the chain of command within a typical formation of a boat group. The pennants and streamers shown in the figure are for identification of the various commanders and are not meant to be actually flown from the boats. The wave guide flags, however, will usually be flown. It will be noted that in waves consisting of only one or two boat divisions, one officer may act as commander of both the wave and a boat division.

d. Personnel requirements of the boat group. -

1. The naval personnel required to command and operate a boat group landing a reinforced infantry battalion in assault may be summarized as follows:

A boat group commander.

Two assistant boat group commanders, if needed, to be employed as wave commanders, or otherwise assist in control of the movement.

One boat division commander for each boat division (usually 6 to 8).

A boat officer or competent petty officer to command each boat not carrying one of the above officers.

Boat crews, with necessary signalmen.

2. This number of officers and men is necessary only for leading boat groups, as troops and material of succeeding landing groups are usually transported by boats of larger capacity. Officer personnel available may also compel modification for leading boat groups. However, a boat group commander with an officer assistant in each wave is considered the minimum requirement. Senior petty officers should then be employed as commanders of boat divisions to which officers have not been assigned.

3. The exact size of the boat crews assigned to man each type of boat to be used should be made known to the landing force before assignments of troops to boats are made.

4. Sufficient specialists in engineering and ordnance should be provided for the necessary maintenance of boats and armament.

e. Transport commanders. -

1. When all boats of a boat group and the corresponding troops are embarked on a single transport, the boat group operates under the orders of that transport commander until it reaches the rendezvous areas when it operates under the direction of the control group commander. In order to insure accurate timing of the movement of the boat group from the rendezvous area to the beach, the approach schedule prepared by the transport commander should be furnished the appropriate control vessel as soon as it arrives in the rendezvous area. (See par. 428f.)

2. When boats of a boat group and troops of the corresponding landing group are embarked on several ships, each troop unit debarks under the commander of the ship on which transported. The loaded boats then assemble at the designated rendezvous areas where they are guided by vessels of the control group to the line of departure.

406. Assignment of boats to boat groups. -

a. The table showing the organization of landing groups (fig. 1) is the basis for the assignment of boats to boat groups. This assignment should be made as early as practicable prior to embarkation.

b. Boat groups which are to carry assault battalions should be assigned sufficient boats to transport them intact in one trip, and should include the smallest and fastest boats available. Boat groups organized to carry units which are to land later may consist of larger motor launches, lighters, etc.

c. Where available, special antiaircraft and close support boats should be assigned to boat groups transporting assault battalions.

d. In determining the number of boats required, the capacity of amphibian tractors included in the landing group should be taken into consideration.

e. The assignment of boats to boat groups may be conveniently issued in the form of a table showing the boats assigned to each group and, if known, the naval officer designated as its commander. The source, type, capacity, and identification numerals of each boat should be given.

407. Boat pools. -

a. These consist of additional boats assigned to transports to aid or replace boats which become inoperative prior to and during the landing. Boat pools should include all types used in the boat groups they support, and crews should be familiar with the plan of landing and the formations involved. Certain of these boats may be used to accompany leading boat groups and, in this case, should operate under the orders of the boat group commander.

b. Boats of leading boat groups carrying troops or matériel will not be permitted to leave formation between the line of departure and the beach to assist damaged boats. Boats transporting succeeding landing groups will be guided by the requirements of the situation.

408. Flexibility. -

a. Prearranged plans cannot be expected to cover every situation that may arise after the force is embarked. It may be necessary to modify the original plans, or to select an entirely new landing area. Hence, the boat groups and the landing groups should be organized, trained, and embarked so as to be able to execute a landing wherever desired in accordance with orders issued at sea. This is possible only when -

The landing groups are organized into well-balanced tactical teams.

Boats for the boat groups have been designated, and the boat groups properly organized.

The personnel is properly trained in suitable boat formations (usually not more than three).

The officers of the boat groups are embarked upon the same transport as the landing groups.

b. If the above conditions are fulfilled, a change of formation for any particular beach becomes relatively simple, involving only a change in the position of complete boat divisions. Minor adjustments may be made, such as changing a boat with its complete load from one boat group or boat division to another, but no change in the basic organization of the boat groups or reassignment of troops to boats should be necessary.

409. Embarkation of officers of the boat group. -

a. All officers of a boat group, including boat officers, should be embarked as a unit on the same transport which carries the officers of the corresponding landing group. This is desirable even if some of the boats of the boat group and their crews are carried in other ships. This doctrine permits the closest personal cooperation between officers of the boat groups and those of the landing groups with whom they must operate under fire. This consideration becomes even more important when the individual boat officers consist of those chosen mainly because of their proficiency in handling small boats rather than experience and training aboard ships of the Navy, as would often be the case in time of war.

b. Furthermore, in case of change of plan while at sea, the embarkation of boat and troop officers on the same ship greatly facilitates the preparation of a new plan for the movement from ship to shore, and the dissemination of the necessary orders and instructions to all concerned.

410. Beach and fire-control party personnel. -

a. Due to the fact that the regular duties of individuals of the naval beach parties do not begin until after they have been landed by the boat groups, they may be used to assist boat crews during the initial movement to the beach, and should be assigned to boats accordingly.

b. Fire-control party personnel for the control from the beach of ships' gunfire may use a boat, or boats, from the firing ship, or may be assigned to boats transporting troop units. If embarked in separate boats, the boat group commander assigns an appropriate position in the boat formation.

411. Marine personnel as crews of boat guns. -

a. Personnel of machine gun and howitzer companies may be utilized as crews of boat guns. Shore-party personnel may be used as gunners, ammunition passers, or to assist the boat crews in any other way during the trip to the beach. The personnel of assault rifle companies should not be assigned such duty, as they should be free to disembark and engage in the fight as soon as the boats ground.

b. If marine personnel is used in manning boat guns, members of the regular boat crews should also be trained to operate these weapons for their own protection during subsequent trips.

412. Distance and interval. -

a. When speaking of formations of troops on land, the term "distance" means the space between elements from front to rear; "interval" means the space between elements of the same line. When speaking of naval craft, the term "distance" means the space between individual ships or boats, measured in any direction; "interval" means the space in any direction between groups of ships or boats, measured between the corresponding ship or boat in each group.

b. The naval designations are used in this publication in connection with boat formations. The interval between waves is expressed in time (minutes), as the linear distance is dependent upon the speed of the boats.

413. Factors involved. - Formations, frontages and distances employed within boat groups are governed largely by the following considerations:

Type of boats available.

Extent of beach, form of coast line, and presence of obstacles.

The necessity of maintaining the integrity of troop organizations and landing these organizations in the desired tactical formation.

The necessity for effective use of boat weapons against enemy aircraft and beach defenses.

Vulnerability of the formation to fire of enemy beach weapons and aircraft.

Time intervals between waves which permit timely support by following units, and, at the same time, are sufficient to prevent congestion of boats and intermingling of units on the beach.

414. The boat division lands the assault platoon. -

a. According to the situation and the terrain, the rifle platoon may land in one or in two echelons. Although the former quickly develops the full fire power of the platoon, it leaves the platoon leader with no force available for reinforcement, flank protection, or maneuver. It may, therefore, be more desirable to land a part of the platoon as a second echelon or support group.

b.

1. Figure 4 illustrates a boat division landing an assault platoon in four boats. This is considered the ideal from a tactical standpoint but the number and size of boats available may compel a more economical loading. In such a case the assault platoon may be embarked in three or even in two boats. A boat division of three boats usually employs a Vee formation as illustrated. A division of two boats usually proceeds in line of bearing (echeloned) to avoid enfilade. The assignment of less than three boats to an assault platoon is avoided whenever practicable as it will delay the deployment of the platoon and increase its casualties.

2. It will be noted that the leading boats are deployed in a Vee, similar to that used by aircraft. This formation possesses the advantage of effective leadership and control by the command and guide boat, permits the three leading boats to fire their weapons at the beach, and is less vulnerable to aerial attack than a line or column formation. Whenever advisable, the Vee may be opened to a line-abreast by appropriate signals from the leading boat. (See sec. VII for

boat formation signals.) In order further to avoid the effects of hostile fire, boat officers should be trained to run zigzag courses while maintaining approximately their relative positions in the prescribed formation.

3. One group of the platoon may be designated as a support group and should follow sufficiently close to the leading boats to maintain contact. As the leading boats approach the beach, the support group should be in the rear from half a minute to 2 minutes traveling time. This allows the support group, while enroute, to choose the most advantageous point, within the platoon's zone of action, to land and support the attack. Care must be exercised to avoid fouling the anchor lines of preceding boats. In the case of a quartering sea, extension of the time interval between waves may be necessary to allow the leading wave to recover anchors before the succeeding wave beaches.

4. Ordinarily, the support group lands behind leading squads which have been able to make a successful landing and advance inland. If, however, unopposed enemy weapons open fire from positions on the flank of the platoon which would obviously endanger the leading squads, the support group should not hesitate to change course so as to engage such weapons with boat guns at point-blank range and land the troops so that they may deliver a direct assault upon the position. Such flanking fire from the beach is particularly dangerous when landing in bays or other indentations. The maneuvering of the support group as described above would, of course, be greatly handicapped in the presence of fog, smoke, or darkness.

5. A rifle platoon, after landing, is held responsible for a frontage of from 100 to 200 yards. In order to cover the entire front with fire and insure all enemy weapons on the beach being engaged immediately upon landing, the leading boats are uniformly distributed over the assigned front, making the distance between boats from 40 to 70 yards. This distance between boats will usually prevent more than one boat being damaged by a single shell or aerial bomb. At night, or when landing on a beach of less than 100 yards, the distance may be reduced.

c. When the leading elements of assault platoons are to be landed in boats carrying more than a squad there should be sufficient distance between boats to allow for the full deployment of the troops from each boat without overlapping on the beach.

d.

1. Figure 5 illustrates the application of the Vee formation of the boat division when landing an assault platoon on one side of a peninsula. This maneuver is particularly applicable where the platoon has the task of covering the flank of other units. The formation permits the weapons in the reentrant. The support group in a separate boat, without reducing speed, maneuvers toward the exposed left flank of the platoon ready either to go in and engage any weapons which open fire along the platoon front, or to land behind the most successful squad.

2. When it is desirable to have an assault platoon attack both sides of a peninsula, the three leading boats split from the Vee formation when nearing the beach and land at the point and two sides of the peninsula, respectively. The support group may then land behind the most successful squad, land on one of the flanks, or be used for reinforcement.

e.

1. Figure 6 illustrates the closed Vee formation used by an assault boat division while proceeding from the transport to the vicinity of the line of departure; the dotted lines show how the boats deploy as they cross that line. Boats are about 40 yards apart in order not to give a concentrated target to enemy aircraft and artillery. The closed Vee facilitates control and deployment into open Vee or line-abreast. In rain, fog, smoke, or darkness, it will usually be advisable to cruise in column formation, with or without boats in tow.

2. In daylight, the deployment into open Vee or line-abreast is normally made on or before crossing the line of departure. When a narrow channel exists, deployment may be delayed until the channel is negotiated. During darkness, deployment may be made closer to the beach. Deployment is made gradually, without material reduction in speed of formation.

415. Rear boat divisions. - Boat divisions in the second and succeeding waves may employ formations similar to the foregoing. Boats should be not less than 40 yards apart and arranged in staggered lines.

416. Landing of the assault company. -

a. The assault company is usually landed by three boat divisions. If the company includes three rifle platoons and a weapons platoon, units of the latter may be attached to the rifle platoons until the landing is effected. A fourth boat division may be organized if practicable and if circumstances warrant such action. When platoons are small, or when only large boats are available, the number of boat divisions may be reduced accordingly.

b. In the advance inland, an assault company of three rifle platoons or of three rifle platoons and a weapons platoon, is usually made responsible for a frontage of from 200 to 500 yards. The frontage of the actual landing will generally approach the lesser figure.

c. The assault company may land in any of the following formations:

Two platoons in assault and one in support.
One platoon as a covering force and two initially in support.
In column of platoons.
Three platoons abreast (exceptional).

d. Two platoons in assault. -

1. Figure 7 illustrates an assault company landing with two platoons in assault and one in support. This formation is applicable when the company lands on a frontage of from 250 to 500 yards.

2. Each of the two leading platoons is transported by a boat division employing four boats. These two boat divisions constitute the first wave. The support platoon, company headquarters, and attached or supporting units are carried in one boat division constituting the second wave.

3. The support platoon should follow the leading wave at such interval as to permit the assault platoons to clear the immediate beach of the enemy, and allow the support platoon a reasonable chance to land behind a successful advance without intermingling of units. On the other hand, if the landing of the second wave is delayed too long, the attack may break down because of platoons being defeated in detail as they arrive at the beach.

4. When the company is making a relatively deep advance, the leading platoons should be given an opportunity to advance from 200 to 400 yards from the beach before the support platoon lands; the distance being greater in open country and less in wooded or broken country. The time it will take the troops to cover the desired distance must be estimated by troop commanders from a study of the terrain and battle conditions that will likely prevail at each particular beach. As land attacks may progress initially at from 30 to 50 yards per minute, the time interval between the first and second waves will vary from 4 to 12 minutes.

5. When the company lands in a bay, the boat divisions carrying the two assault platoons may be directed to separate when nearing the beach, in order to permit the platoons to attack both sides of the bay. Under cover of these attacks, the support platoon may land in the interval and attack the center of the beach.

e. Platoon as covering force. -

1. Figure 8 illustrates the assault company employing one platoon as a covering force and two platoons abreast in the second wave. A covering force is one whose primary task is to clear the beach of enemy resistance and to secure sufficient ground to protect the beach from close observation and direct fire. This task requires that the leading squads move in any direction necessary at the time and promptly charge enemy groups wherever found. As troops faced with such a contingency may soon become scattered and disorganized, a covering force should be given a limited objective. Succeeding units are used to carry the attack forward. In this illustration, the covering platoon lands on the whole company front and rushes the immediate beach defenses. It is expected to overcome most of the enemy groups found near the water's edge, and should not therefore be expected to continue the advance to any great depth.

2. Under protection of the engagement of the covering platoon, the two following platoons land, pass through it, and launch a fresh attack. The covering platoon is then assembled for use as company support, due allowance being made for its initial efforts.

3. This formation is applicable when the company is to land on a frontage of less than 200 yards and then fan out shortly after landing to cover a broader front. It may be necessary to close the Vees in the second wave sufficiently to conform to the limits of the beach.

f. Column of platoons. -

1. Figure 9 shows an assault company landing in column of platoons. This formation is applicable when the company is landing on a beach of less than 200 yards and is not required to extend its frontage to any considerable extent after landing. The formation may also be employed to prevent congestion on a very restricted beach, which might occur if two platoons were landed abreast.

2. As this formation facilitates the concentration of enemy shore weapons on each boat division in turn, and exposes the platoons to defeat in detail, the time interval between boat divisions should be reduced as much as possible without entailing congestion of boats and intermingling of platoons at the beach. A time interval of from 2 to 6 minutes is desirable. When the company is being employed as a covering force for the battalion, the intermingling of platoons after landing ceases to be a governing factor, and the time interval for landing of boat divisions should approach the minimum figure.

3. It may be necessary to employ the column formation in approaching the beach in order to negotiate a narrow channel. If the beach is of sufficient extent to permit platoons landing abreast, the passage of the channel may be made in column formation with short intervals (200 to 300 yards) between boat divisions. This would permit platoons to break out of column upon passage of the channel and land abreast almost simultaneously.

g. Platoons abreast. - The assault company will seldom land with all three platoons abreast. As all platoons of the company are immediately engaged, the formation permits little opportunity for the company to maneuver on shore, and it cannot be expected to do more than deliver a severe attack on the enemy groups close to the beach. Here, initially supported by all boat guns, its full fire power is immediately brought to bear. This formation may be applicable when the company is acting as a covering force for the battalion landing on a broad front.

417. The boat group lands the assault battalion. -

a. In the advance inland, the assault battalion is assigned a frontage of from 500 to 1,000 yards. A battalion taking part in the main effort should rarely be assigned a frontage greater than 600 yards. In many cases, the beach will not be of sufficient extent to permit a battalion to land so as to cover initially its whole zone of advance.

b. The battalion may be landed with two companies in assault and one in reserve; one company in assault and two initially in reserve; column of companies; or three companies abreast.

c. The assault companies may employ any of the formations enumerated in paragraph 416c. This permits a wide choice in battalion formations to suit any particular beach conditions.

d.

1. Diagram A, figure 10, shows two companies in assault and one in reserve, with each leading company employing two platoons in assault. This battalion formation permits an initial attack on a beach of from 600 to 1,000 yards, with a battalion reserve available to extend the front or drive through to greater depth. The same battalion formation may be used for frontages less than 600 yards by having either one or both of the assault companies attack in column of platoons.

2. This formation is particularly applicable when the coast line is regular, and open country extends inland for a considerable distance. Under these conditions it is desirable that the first troops to land have sufficient power to drive in quickly toward the battalion objective. When the battalion beach consists of a bay, the two interior assault platoons may be slightly echeloned to the rear to permit the sides of the bay being attacked first by the exterior platoons. The main disadvantage of this formation lies in the fact that almost half of the battalion is in the first wave and therefore immediately committed to the fight at the water's edge.

e.

1. Diagrams B, C, and D of figure 10 show various means of employing a covering force. For explanation of the use of a covering force see paragraph 416e above. The use of a covering force by the battalion is applicable when it lands on a beach of less than 500 yards. It is particularly suitable when the terrain adjacent to the beach is such that a short advance of the covering force will afford the desired protection for the landing and deployment of succeeding units.

2. Diagram B illustrates one company as covering force with two platoons in assault and one in support. The remaining companies of the battalion land abreast. This formation has the advantage of having one company commander in charge of the first attack on the beach, with a support platoon at his disposal to influence the action. The remaining two companies, landing abreast, are in proper formation to pass through the covering force, continue the attack, and extend the front. However, in this formation, the whole battalion is committed to a single course of action soon after landing, and the absence of a reserve company, free to be launched in any direction by the battalion commander, is a distinct disadvantage.

3. Diagram C shows two companies in assault and one in battalion reserve. Each assault company employs a platoon as covering force, thus making the covering force weaker by one platoon than that shown in diagram B. This formation, however, has the distinct advantage of providing initially a mobile battalion reserve to meet contingencies. It is particularly applicable when the battalion lands on two separate beaches and only a short advance of the covering force is required to furnish the desired security.

4. Diagram D illustrates one company as a covering force, followed in column by the other two companies of the battalion (column of companies). This formation tends to divide the landing into a succession of three efforts of equal magnitude. This feature may tend to increase the danger of defeat in detail and slow up the process of extending the front. The formation has the advantage inherent in a disposition in depth and may be desirable when the battalion lands in darkness, when it attacks inland on a narrow front, or to prevent congestion on a very restricted beach.

f. The battalion will seldom land with all companies abreast. The formation may be applicable when a demonstration is desired to create the impression of a much larger force, or when it is necessary to make a reconnaissance in force over an extremely broad front with a view of determining enemy weakness and utilizing other battalions to exploit a successful landing on any part of the front.

g.

1. In diagrams A, C, and D of figure 10, the battalion reserve, consisting of an infantry company with machine guns, mortars, and other battalion weapons is embarked in one boat division.

2. The most desirable landing place for battalion reserves can seldom be foreseen before the assault companies land. Therefore, sufficient time interval should be allowed between the landing of assault companies and the reserves to insure an opportunity, while en route to the beach to divert the reserves to a landing behind a company that has already succeeded in getting ashore. On the other hand, this time interval should not be so great as to expose an assault company, which has succeeded in landing, to defeat on the beach for lack of timely support. A time interval between 5 and 15 minutes is applicable to most situations. The determination of the landing place of battalion reserves should be made by the battalion commander.

h. The battalion weapons company is assigned positions in the boat group in accordance with its proposed tactical employment ashore. For the landing, it is generally desirable to attach a machine gun platoon to each assault company and land the remainder of the battalion weapons company with the battalion reserve. In the event additional antiaircraft and antitank weapons are assigned from higher echelons, these should be embarked in a separate boat division, and the weapons of this type in the battalion weapons company may be attached to assault companies in order to facilitate early employment ashore.

i. The battalion headquarters company is generally distributed within the boat division carrying the battalion reserve. Attached and supporting units may be included in the same boat division or carried in a separate boat division.

j. Antitank and antiaircraft weapons and crews are attached to the assault battalion from units of higher echelons in situations where their early employment is probable. Since it may become necessary to modify the composition of landing groups to meet the requirements of the situation, these weapons should be embarked in a separate boat division to facilitate their redistribution. This boat division is usually included in the same wave with the battalion reserve.

k. Fighter planes of the attack force usually have the task of protecting the landing area from action of enemy aircraft. Additional protection must be provided against aircraft which may evade friendly fighting squadrons. This is provided by the following:

Fire from antiaircraft guns of vessels of the inshore support groups.
Fire from boat guns.
Fire from automatic rifles of the landing groups, both while embarked in boats and after landing.
Fire of antiaircraft weapons of the assault battalion and of antiaircraft weapons which may be attached from higher echelons.

418. Landing of regimental, brigade, division, and force reserves. -

a. In order to exploit quickly the successes gained by leading battalions, reserve units must be available for prompt landing. Sufficient boats should be provided to land at least the assault elements of the regimental, brigade, and division reserves in a single trip. When a shortage of boats makes this impossible, consideration should be given to reducing the frontage of the initial attack in order that reserves may be immediately available in small boats ready to land when required. In order to facilitate control, reserves are preferably embarked in relatively large boats.

b. The proper time and place of the landing of regimental, brigade, division, or force reserves can seldom be foreseen until information has been received of the progress of the combat on shore. Upon debarkation, boat groups carrying reserve battalions proceed to some designated sea area where they receive orders from the marine commander of the tactical unit of which the reserves form a part as to the point of landing and when to start. This area should be centrally located in reference to their probable landing places, and at a reasonably safe distance from shore artillery. It will often be desirable to designate one of the vessels of the control group as the rendezvous, as this would facilitate prompt transmission of orders. As information regarding the progress of the attack may be available to the commanding officer having authority to move the reserves by H plus 15 minutes, the reserves should be in their designated area by this time.

c.

1. Where the beaches on which the reserve units may be landed are separated by long distances, it may be desirable to hold the units aboard the transports, even though boats are available for their immediate debarkation. When a decision is reached regarding the employment

of these reserves, the transports proceed opposite the selected point of landing for debarkation, thus speeding up the movement.

2. When it is necessary to land reserves in the second trip of the boats, the transports or other vessels (such as destroyers) to which the reserves may have been transferred, should proceed as close to the beach as enemy fire and depth of water permit. Under such conditions, provision must be made for the rendezvous of boats with the transports or other vessels at the selected point.

3. When conditions permit, reserves may be landed directly from transports and smaller craft onto a dock or sea wall. The landing of reserves directly from beached transports, however, generally involves the use of small boats or rafts to ferry the troops to the beach. Under these conditions, time will usually be gained by having the transports or other vessels anchor or heave to in sufficient water to keep them afloat, even when it involves a slightly greater ferrying distance to the shore.

419.0 Landing schedule. -

a. A landing schedule is prepared for each operation and issued as an annex to force operations orders. It shows the place, hour, and priorities of landing of all units, and coordinates the movements from the transports, in order to provide for the execution of the desired scheme of maneuver.

b. In a division, or for smaller detached operations, the landing schedule will usually be issued by the division or the unit conducting such detached operation. Priorities of landing in the second and succeeding trips of the boats should be prescribed by the highest echelon of command.

c. The time of landing of units landed in the first trip of the boats is usually expressed in terms of H-hour. The hour of landing is not prescribed for units transported in the second and succeeding trips of boats running individually. Such units are listed in order of priority of landing from each transport.

d. A suggested form for a landing schedule is shown in figure 11.

e. It will be noted from the following paragraphs that prior to the issuance of a landing schedule for a specific operation, most of the detailed plans can be prepared, and training conducted, for the debarkation and movement from ships to shore from each transport.

420. Detailed plans. -

a.

1.Detailed plans for the debarkation of all troops from each transport and the movement from ships to shore of all leading boat groups should be accomplished jointly by the commanders of the landing groups and boat groups concerned, under the direction of the transport commander, and in accordance with the landing schedule and other orders from higher authority.

2. As the time and place of landing regimental, brigade, division, and force reserves depends mainly upon the progress of the troops previously landed, the decision as to where these reserves should land and when they should start should rest with the marine commander of the tactical unit of which the reserves form a part. (For manner of landing such reserves, see par. 418 above.)

b. The use of diagrams in preparing and issuing plans and instructions will be found useful. Diagrams should be simple and clear, and, to facilitate reproduction, should be accomplished by use of the typewriter, as shown in the figures in this section.

c. The organization of the landing groups, and the assignment of boats to the corresponding boat groups having been completed, the following diagrams, tables, and schedules will be found useful in planning and issuing orders for the movement from ship to shore:

1. Boat assignment table showing the organization of boats into boat divisions, boat division formations, and the personnel carried in each boat.

2. Landing diagrams showing graphically the various landing formations of the boat group.

3. Deployment diagrams, used when necessary to show graphically how the boat group deploys into the various landing formations.

4. Boat diagrams showing the place of individual men and equipment in each boat.

5. Boat assembly and rendezvous diagrams showing the assembly areas of empty boats preparatory to debarkation, routes to gangways, and rendezvous areas of loaded boats.

6. Debarkation and approach schedule containing the instructions necessary to insure troops being debarked from transports and landed in accordance with the prescribed plan.

421. Boat assignment table. -

a. Explanation of table.--

1. The information shown by the boat assignment table for a boat group landing an assault battalion is illustrated in part in figure 12. This table should be accomplished as soon as the composition of the landing group and the number, types, and speeds of boats assigned to the boat group are known.

2. It will be noted from the figure that in each boat division the order of boats in column is determined from, and facilitates deployment into, the Vee formation. (See fig. 6 for further illustration.

3. Each boat division commander and the commanding officer of the troops to be carried are placed in the leading boat of the boat division.

4. Boats of each boat division, together with the troops they carry, are listed in the table in the order they appear in their column formation. This will be the order in which the boats or each boat division come alongside the transport for debarkation of troops.

5. Matériel which requires extra boat spaces, such as mortars, guns, bulky ammunition, etc., should also be shown in the table wherever necessary.

b. General organization and assignment doctrine. - In the organization of boat divisions, the determination of their formations, and the assignment of troops to boats, the following points should be kept in mind:

1. A separate boat should be assigned for use of the boat group commander and his necessary communication detail. If sufficient boats are available, it is also desirable to assign a separate boat to each of the assistant boat group commanders. The landing group (battalion) commander, with a part of his staff, should land in one of the above-mentioned boats, preferably

that of the boat group commander. These boats are not placed in any boat division, but cruise independently as directed by the officer concerned.

2. The smallest and fastest boats should be assigned to assault platoons in such a manner as to permit the battalion to assume the maximum number of formations, the next larger types to support platoons, and the largest boats to the reserve echelon. Boats in each boat division should have approximately the same speed. Boat divisions which will probably land abreast should also have the same speed.

3. It is desirable that at least four platoons per battalion be assigned boats suitable for assault echelons. This would not only permit the battalion to land on a broad front (as shown in diagram a, fig. 10) but also to land in either of at least two additional formations.

4. The integrity of troop units should be maintained as far as possible, and units should be landed in their proper tactical formations. For example: A rifle squad should be kept together on one boat; each platoon in a reserve rifle company should be kept intact in one boat (or boat division); etc.

5. The risk of heavy loss of any one arm or service is reduced by distributing each among two or more boats. For example, it would be inadvisable to embark all of a weapons company, communications platoon, or similar organization, in one boat.

c. Suggested procedure. - In the preparation of the boat assignment table it may be convenient to proceed in the following sequence:

1. Assign a separate boat for the boat group commander and his communication detail, and, if sufficient boats are available, one for each of his assistants.

2. Assign to a boat the landing group (battalion) commander and such members of his staff as should accompany him.

3. Assign such members of the weapons company, and beach party and shore party personnel, as are needed as gunners or to assist the boat crews in the initial movement.

4. Assign boats to rifle units--first, assault platoons, then support and reserve echelons. This is the basis of the organization of the boat divisions.

5. Assign the remainder of the weapons company, headquarters units, and any attached or supporting troops. Such units are assigned to boats carrying rifle units or to separate boats. Such separate boats are assigned to or organized into boat divisions as necessary. A separate boat division may be organized for large self-contained units such as headquarters companies or artillery.

6. Designate ambulance boats and assign the necessary medical personnel and equipment in accordance with the attack force medical plan.

7. Fill up boats with the remainder of the beach and shore parties.

8. It is advisable to employ a complete check-off list, in order that each unit, or fractional part thereof, can be accurately accounted for. As a final check, the total of the boat spaces used should be added and compared with the total shown on the check-off list.

9. Beginning with "Boat Division No. 1," assign each boat of the boat group its serial number. Each type of boat is given a designating letter. Boats of each type are numbered serially in the order they should load and proceed from the transport; for example LCP(R)-1, LCP(4)-2, LCP(4)-3, LCV-1. These designating letters and numbers are for tactical purposes only, and indicate the proper position of the boats while in formation. For administrative purposes when not operating in formation, boats will be known by their permanent designations as "TENN 2," "ARG 4"; except that when boats have no permanent designations, their tactical type letters and numbers may be used.

10. In order to prevent duplication, blocks of designating letters and numbers may be assigned each boat group. For example, Boat Group No. 1 may be assigned LCP(R)1-14, inclusive; Boat Group No. 2, LCP(R)15-29, inclusive; etc.

11. The designating letter and number are placed on boards which can be suitably displayed in the boats. Such boards should be provided by the transport in which the troops are embarked and should be carried into the boats with the troops. This will insure, in any contingency, the proper identification of each boat according to the troop units actually embarked.

422. Landing diagrams. -

a. A landing diagram shows the landing formation of the boat group and the guide and alternate guide of each wave. A separate diagram is made to show each formation the boat group may be required to employ, generally from two to four, depending on the types of boats available. For later reference, each formation should be given an identification number. Figure 13 shows a sample landing diagram for a boat group with four boat divisions in the first wave. Additional information, such as the designating letter and number of each boat, may be included on the original diagram if space permits. Such additional information, together with the intervals and distances between elements, should always be added if for any reason the diagram alone is to be used for a particular operation in lieu of written orders issued in advance.

b. Landing diagrams should generally be prepared and promulgated at the same time as the boat assignment table.

c. The intervals and distances between the various elements of the boat group will vary for different beaches and should, therefore, be prescribed in the orders (or placed on the diagram) for each rehearsal, and for the actual landing. For example, instructions for a particular rehearsal or actual landing, employing the formation shown in figure 13, would include information similar to the following:

The boat group will employ landing formation No. 1:

Distance between boats within BD's - 50 yards. Support groups in first wave - As directed by boat division commanders.