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Force Instructions No. 25





AUGUST 16, 1918

Force Instructions

No. 25


Doctrine and General


Addenda to and revision of certain parts of Force Instruction

No. 2, of September 22, 1917.1


U. S. Naval Forces in European Waters.

Force Instructions, No. 25.





     These General Instructions are based on the experience gained in the actual war zone by the anti-submarine forces of this Command. They set forth, as a general guide, those operating methods that are considered by our officers to be the best thus far developed.

     Wherever out forces are operating under the direct command of officers of the Allied services, these instructions cannot, of course, be followed when they are in conflict with the published orders or policies of the Allied Commander concerned.

     As it is important that our experience in this war be made a matter of record; and, further, that the lessons derived from this experience be embodied in written form for the information of new forces joining, it is earnestly requested that, whenever it appears desirable to make additions to these instructions, or changes in them, prompt notification be conveyed to the Force Commander, together with a record of the experience that seems to justify the proposed additions or changes.


Mission and General Plan

     No operation should be undertaken without a clear statement by the officer in Command of the operation of the immediate Mission which is to be accomplished.

     The General Plan should invariably be clearly state in paragraph 2 of the order covering the operation.

     The General Plan is a positive order which must be kept clearly in mind by all subordinates; local interests must not be allowed to cause deviation from it. It should leave as much initiative to subordinate as possible. It must be constantly referred to for the purpose of interpreting the more detailed instructions which usually follow in paragraph 3. It is manifestly impossible for the Commander of the operation to give detailed instructions in advance that will cover all emergencies; it is equally impossible for the Commander of an operation to give these instructions on the spot to meet adequately a local situation suddenly developed. Hence the importance of having the immediate Mission and General Plan clearly understood in advance, and the necessity for leaving as wide an area of discretion to subordinates as possible.

Individual Initiative

     Absolute loyalty to the General Plan is a prime military requisite because without it team work is impossible. Therefore, individual initiative should be directed towards furthering the general Plan. No officer should fail to exercise his initiative and judgement in support of the General Plan when confronted by unexpected conditions. New conditions, or conditions not contemplated in the operations order, may require him, for example—

(a) To profit by an advantageous situation in such a manner as will conform to the general Plan.

(b) To extricate force from a disadvantageous situation.


Allied Naval Mission in the present War

     The basic Naval mission of the Allies in this war is—

“To further a successful decision on Land.”

     The best means of bringing about sea conditions favorable to success on land lie in the establishment of command of the sea. When command of the sea is obtained, resources of the friendly and neutral world are made available for the logistical support of the Allied peoples and their armies; and these gain the strategic freedom offered by the sea to strike with land forces at the enemy’s shore power in otherwise inaccessible places, while the enemy is at the same time correspondingly restricted. The General Naval Mission is, therefore—

“To obtain command of the Sea.”

     Command of the sea may be established either:

(1) By destroying enemy naval forces.

(2) By effectively containing them.

(3) By so nullifying the effect of their activities as to reduce it to negligible proportions.

     At the present time the Allies have command of the surface of the sea, but have not command of the sub-surface of the sea. Their special and immediate mission, therefore, is:

“To obtain sub-surface command of the Sea while still retaining command of the surface of the sea.”

Sub-surface of the sea may be obtained:

(a) By the destruction of all Submarines.

(b) By the blocking of all submarines in port.

(c) By nullifying the effect of submarines if they are at sea.

     The conditions of the present war have required that operations of all three types proceed simultaneously, but it is obvious that the destruction of submarines is the most efficacious method of obtaining sub-surface command of the sea.

     The destruction of one submarine has been estimated to be approximately equivalent to saving 50,000 tons of shipping per year.

     For humanitarian reasons, survivors from sinking ships must be rescued.

     American vessels are not engaged in blocking submarines in their ports, so that their present missions in this war are:

(a) To destroy submarines.

(b) To protect shipping.

(c) To rescue survivors.

     The accomplishment of these missions requires:

(a) The maximum effort to make tactical contact with enemy submarines consistent with the special nature of the operations in hand.

(b) The maximum tactical use of every contact with enemy submarines.

(c) The most efficient disposition and cruising arrangements of escorts.

(d) Arrangements for handling survivors.

     As to (a), every force making passage alone should deploy into a scouting information.

     As to (b):

(1) A determined attack by at least a large proportion of each force which comes into close contact with an enemy submarine should be made regardless of the nature of the duty upon which our forces may be engaged.

(2) Each vessel engaging in an attack should use depth charges freely.

(3) once contact has been made a persistent effort should be made to maintain it, or regain it if lost.

(4) Rescue work and the immediate protection of merchant shipping should be subordinated to the duty of destroying submarines, unless circumstances are very exceptional, as to which the Senior Officer present must be the judge.



     Doctrine is a bond of mutual understanding governing the application of principles to circumstances.

     Attention is invited to the Navy Department’s Confidential Circular on Doctrine, dated December 1, 1917.2 It is hoped that many officers will find it possible to devote serious study and attention to the sound doctrine based upon war experience. It is the officers afloat who have the opportunity of actual experience, upon whom principal dependence must be placed for the development of sound doctrine.


Tentative Doctrine of Anti-Submarine Attack

     The enemy’s submarine campaign cannot be defeated by defensive measures alone.

     The system of escorting convoys is in part a deployment in readiness, and serves to bring hostile submarines into close contact with a concentrated force of our anti-submarine vessels more frequently than in possible by other means.

     It is imperative that full advantage be taken of such contacts to destroy the enemy; to accomplish this the role of escorts of anti-submarine types must be transposed instantly upon contact with an enemy submarine from defensive to offensive and vigorous counter-attack prosecuted.

     To cover such cases the following is tentatively prescribed as:

Counter Attack Doctrine

     1. The maximum possible advantage must be taken of each and every close contact with an enemy submarine to pursue it to destruction. The mission of protecting the convoy becomes secondary to that of destroying the submarine.

     2. The pursuit and attack should be continued until no reasonable hope of destroying the submarine, or of sighting it again before dark, exists. An exception may be made in the case of a troopship convoy; but the pursuit shall even then invariably be made by one more or the escort.

     3. As a rule, every close contact with an enemy submarine shall be made the occasion of an intensive attack with depth charges. There should be no hesitation to expend all depth charges, if the chance of destroying the enemy would be increased thereby. In every case the attack should be as heavy and persistent as is practicable in the circumstances.

     4. Even when the attacking submarine is not seen, a number of depth charges should be dropped if there are any means of judging its probable position.

     5. All officers should make a constant study of the problems of attack confronting the submarine, with a view to developing anti-submarine tactics, thereby insuring the use of depth charges to the best possible advantage.


Tentative Anti-Raider Doctrine

     The conditions which may attend the attack on a convoy by enemy raiders or cruisers are so diverse that no orders or precise instructions governing the conduct of the escorting destroyers in such even can be formulated. It is necessary, therefore, that a well-understood doctrine upon which destroyers may base their actions in such cases be formulated. The following is tentatively put forth:

(1) The best means of protecting a convoy is an attack on the threatening enemy; hence the maximum of offensive power available should be used against him.

(2) A daylight attack by destroyers on a surface raider of superior gun power should be delivered simultaneously from different directions.

(3) To provide against the raider escaping, after either having accomplished his mission or having failed, at least one destroyer should always be designated to track the raider, avoiding risk of damage to herself. The tracker should keep contact with the enemy and send out information frequently.

(4) When an attack by raider is imminent, the Convoy should head on a course opposite to the bearing of the raider at highest speed and be prepared to disperse when ordered. All destroyers, except the one designated to keep touching with the raider and track it, should attack in accordance with battle plan prepared by the Senior Officer of Escort before leaving port.


     A Troop Convoy is a convoy comprising ships carrying troops. Troop Supply Ships may also be found in such convoys. It is customary for ships carrying troops to be commanded by naval officers; Troop Supply Ships may, or may not, be commanded by naval officers.

     A Mercantile Convoy is a convoy composed of Merchant Ships. In such Convoys there is frequently a Commodore of the Convoy who controls the Convoy and is responsible for its navigation.

     An Ocean Escort is a cruiser, Armed Merchantman, Commissioned Escort Ship, or Special Service Vessel, used to protect the Convoy outside the zone of submarine activity.

     A Danger Zone Escort is a group of fast vessels, such as Yachts, or Destroyers, assigned to protect a Convoy within the submarine danger zone.

     A Coastal Escort is a group of smaller patrol Vessels (Trawlers, Drifters, etc.) used as protection for small convoys, or of single vessels, making passage between ports of loading of ships and ports of Assembly of Convoy, or between coastal points on regular voyage.


     One of the principal advantages of the Convoy system is, that in order to sink merchant ships, then enemy must come into close contact with our anti-submarine craft. It is, therefore, highly important that escorts keep in mind their offensive function. A distinctly offensive attitude on the part of escorting ships will afford the best protection to the convoyed ships, and will at the same time favor the protection of a much greater number of merchant ships in the future through destruction of hostile submarines.

     Whatever may be the TEMPORARY duty of Destroyers assigned to Patrol or Escort duty, their most important task is:

     To make the best tactical use of situations and events for taking the offensive against submarines. (See Counter Attack Doctrine, page 5.)

     When submarines are reported ahead of Convoy and in the line of its advance, one of the destroyers (if circumstances render it possible) should proceed at high speed towards the reported position of the submarine for the purpose of attacking or forcing the latter to submerge and to remain submerged until her batteries are exhausted.

     The Senior Officer Present in or with a Troop Convoy commands the entire Force and may exercise such command fully, but it is normally advisable that the tactical handling of the Convoy be left to the Commander of the Convoy and the tactical handling of the Escort to the Commander of the Escort. The Senior Officer in the Danger Zone Escort commands the Escorts, and is responsible for it as well as for the defense of the Convoy.

     The same general principles govern both Troop and Mercantile Convoys. Escort Commanders are expected to deal with special situations that may arise according to their best judgement; they are not to consider themselves limited as to action they may take.

     The principal points to consider in connection with Convoys are these:

(a) Assembly.

(b) Formation.

(c) Station keeping.

(d) Orders in case of separation.

(e) Navigation of Convoy.

(f) Signals.

(g) Radio.

(h) Time.

(i) Miscellaneous.

     (a) Assembly—The Escort Commander should explain in detail at the port of assembly before the time of sailing the orders issued by him to the Convoy.

     The Commodore of the Convoy should explain to the Masters and Chief Engineers at the port of assembly, before the time of sailing, the local methods governing the assembly of the convoy and the regulations governing them after assembly.

     (b) Formation—A formation must be decided upon and all vessels informed as to which ship is guide and as to own place in convoy. As convoys are usually assembled behind boom defenses, vessels nearest the gate should weigh and proceed out in advance of those farther away. Convoy proceeds in column through swept channels and forms when clear of channel. Each vessel has a distinguishing number (flags); this should be kept flying until convoy is formed up and then hauled down. The number of ships in convoy and escort will determine the formation to be used.

     In general, when passing through submarine waters, the depth of formation should be as small as possible consistent with proper tactical control of convoy. Column formation, except when passing through swept channels, should be avoided while in the zone of submarine activity.

     Interval.The interval should not be greater than 800 yards.

     Distance.The distance should not be greater than 500 yards.

     Position of Valuable Vessels.The most valuable vessels, or transports requiring the greatest protection, should be placed in the center of the formation—the least valuable ones on the flanks.

     (c) Station Keeping.Ship must keep proper bearing and distance. If they forge ahead or drop astern other vessels are thereby endangered. The number of escorting vessels is not sufficient to afford proper protection if distances and bearing as ordered are not preserved. The leading ships keep a constant compass bearing from the guide (90° from the base course). If a ship is prevented from keeping proper station on account of a ship ahead dropping back, others should ignore her and gain their proper stations relative to the guide.

     Keeping Closed.Convoys should be kept closed up even if speed has to be reduced to accomplish this. If a vessel suffers a reduction in speed due to accident, an appropriate escort should be left with her if the number of vessels forming the escort warrants such action.

     (d) Rendezvous.A rendezvous should be provided for each day two days ahead; it should be designated by the Senior Officer Present. Positions of Convoy or ships should not be sent out in latitude or longitude, but in bearing and distance from known rendezvous.

     Dispersal of Convoy.When a Convoy is broken up by weather, enemy action, or other cause, the scattered vessels should be rounded up in small groups and proceed under escort of the destroyers in touch with them.

     (e) Navigation of Convoy.The Guide ship is responsible for steering the courses and maintaining the speed prescribed in the sailing orders. Any deviation from speed or course must be notified to the Escort Commander. Noon positions must be signaled to Escort Commander. Have it understood as to whether courses signaled are true or magnetic.

     Zigzagging.Convoys should not zigzag on dark nights, nor in foggy or thick weather. When a fog shuts down on any part of the convoy all vessels must, without signal, take base course immediately and cease zigzagging. In general, no zigzag should be used which involves changes of course more than 45°.

     Changing Course.Changes of course at night or in thick weather should be previously notified to all vessels in the formation; signal of execution should be made by radio and whistle.

     Destination of Convoys.Convoys should make their port of destination during daylight; they should be kept underway continuously without reducing speed in order to accomplish this.

     (f) Signals.Repeat flag signals flag for flag. In semaphore signaling, have each word acknowledged by receiving ship. All ships should keep a lookout on the senior escort vessel and on guide ship for signals. The guide ship should make all signals for courses and speeds.

     (g) Radio.Merchant ships must keep their radio operators on watch at certain specified hours and always when a change of course is to be made during darkness or thick weather. All radiogram must be in code. Upon any alarm, radio stations should be manned.

     (h) Time.The time used on all clocks must be the same. In the danger zone the time of Greenwich meridian (civil date) counted from midnight, shall be used east of latitude 20° West. All signals, radiograms, reports, rendezvous, arrivals, etc., shall be based on this standard time.

     Time signals shall be made twice daily by the Senior officer Present, in order to have all clocks set accurately to the standard time adopted.

     (i) Miscellaneous. Detaching Escort Ships.The detachment of one of the Escort to investigate strange vessels passing the convoy at a considerable distance is not warranted while the convoy is in the submarine zone, unless there is some particular reason to suspect such vessels of being hostile in character, or engaged in un-neutral service.

     Information.The courses and locations of all convoys that are likely to cross should be known in order to avoid collision on dark nights or in thick weather.



     The principal points to consider in connection with Escorts are:

(a) Number of vessels in escort.

(b) Designation of vessels in escort.

(c) Scouting formation when not with Convoy. (Scouting methods).

(d) Contact with Convoy.

(e) Escort formation.

(f) Speed.

(g) Casualties to transports. (Include Rescuing Survivors).

(h) Towing disabled vessels.

(i) Radio.

(j) Internal dispositions.

     (a) Number of Vessels in Escort.The number of escorting vessels assigned to a convoy depends on several factors; among them;

(1) Number of vessels in convoy.

(2) Size of vessels in convoy.

(3) Number of troops on board.

(4) Number of submarines supposed to be near route of convoy.

     While no hard-and-fast rules can be laid down, the following table gives the approximate number of escorting vessels that should be provided for troop convoys under average conditions, when vessels are of moderate size:

     Transports              Escorting Vessels

          1 - - - - - - - - - - -  3

          2 - - - - - - - - - - -  4

          3 - - - - - - - - - - -  6

          4 - - - - - - - - - - -  7

          6 - - - - - - - - - - -  8

          8 - - - - - - - - - - -  10

          10 - - - - - - - - - - - 11

          12 - - - - - - - - - - - 12

          14 - - - - - - - - - - - 14

     (b) Designation of Vessels of Escort.As a rule tactical units should be split up as little as possible in making up escorts, to the end that the efficiency of escorts may be increased through continuity of association of vessels.

     The vessels in each escort should be numbered serially, the serial numbers corresponding to the seniority of the Commanding Officers. Escorts may be divided into two or more sections depending on tactical requirements. Thus, in an escort of 10 vessels, they would be numbered 1,2,3,4,5,6,7,8,9,10, in order of seniority of their Commanding Officers. If divided into two sections, the first section would be Nos. 1, 3, 5, 7, 9, and the second section would be Nos. 2, 4, 6, 8, 10—Section leaders would be Nos. 1 and 2.

     (c) Scouting Formation when not with Convoy.Escort vessels proceeding in company without convoy should form a scouting line to sweep for submarines. Scouting line should be formed as outline in Flotilla Doctrine. Ten vessels would be formed as follows:

10 – 8 – 6 – 4 – 2 – 1 – 3- 5 – 7 – 9

     All officers should be familiar with the general problems of scouting as set forth in Pye’s “The Service of Information and Security.”3

     (d) Contacts with Convoy.When contact with convoy is made the vessel making contact should broadcast “Contact,” giving time, bearing, etc. All vessels should acknowledge contact signals by a special message to Senior Officer’s ship and to vessel making contact; the radio operator’s acknowledgment is not sufficient. Vessel making contact should make smoke for a short interval to indicate her position to others as may be necessary. In case of separation isolated vessels should be kept informed of Escort movements and position relative to a position previously known to all vessels of the Escort when they were together in formation.

     (e) Escort Formation.In all Escort formation the points to be considered are:

(1) The probable sector from which submarine will attack.

(2) Time and probable distance from which attack will be made.

(3) Conditions most favorable for submarine to make an attack.

     Any holidays due to temporary absence of Escorting Vessels must always be covered by adjacent vessels necessitating increased speed on their part.

     The Escort should be informed fully of the zigzag plan of the convoy, so that it may time its own movements to the movements of the convoy; this is especially necessary with fast convoys.

     Suggested formations based on experience to date are shown in the diagrams at end of book.

     (f) Speed.In general, the higher the speed used on Escort Station the better is the protection afforded the convoy.

     Speed should be governed by the speed of the convoy, distance to be patrolled on Escort Station, state of sea, and fuel conservation. Speed of advance is distance made good per hour on base course.

     (g) Casualties.In case one of the vessels of a convoy is torpedoed, the safety of other vessels of the convoy should not be jeopardized in an effort to rescue survivors from the torpedoed vessel. In such circumstances the doctrine of counter-attack is to be followed, leaving one or two of the escorting vessels nearest to the damaged vessel to render her assistance.

     When approaching a sinking ship, boats, or rafts for the purpose of effecting rescue, circle around at highest speed in a spiral. Hunt for submarine first. Look for oil slicks. If torpedoed vessel has just been struck, look for wake of torpedo or firing slick. Drop depth charges on suspicious swirls, slicks, etc.

     If two or more escorting vessels are simultaneously engaged in this work one of them should circle around, keeping lookout for evidences of the proximity of submarines, while others pick up the survivors. In all circumstances be sure that the dangerous sea area is explored before stopping to effect rescue.

     When the vessels that first pick up survivors have the maximum number on board that they can carry they should join the convoy, and others should be sent back for the remainder of the survivors, if any. Survivors may be transferred to other vessels of the convoy, if it can be done with safety.

     In the event of a disaster to any vessel of the convoy, due to collision or other marine risk, and not to enemy action, the situation is reversed; in such case, unless the convoy is in dangerous waters, the primary mission is to save the damaged vessel or to save the personnel in case the vessel is lost. If the locality is such that submarine attack may reasonably be expected, the safety of the undamaged vessels of the convoy is the first consideration.

     (h) Towing Disabled Ships.Light craft should not attempt to tow heavy vessels. A destroyer may take another in tow; but no tow should be taken unless there is another armed vessel present for escort duty.

     (i) Radio.The use of Radio must be reduced to a minimum and the minimum power to reach destination shall be used. A radio spark may indicate to the enemy your direction. Division radio calls and section radio calls shall always be designated.

     A definite order of radio acknowledgements should be decided upon and prescribed.

     Unless there be some special reason against it, the leader of the second section shall be radio relief ship. He should inform escort leader of calls apparently not heard by No. 1 and of any apparent errors in messages sent out by operators of escort commander’s vessel.

     As the success of all operations is, in a measure, dependent upon radio efficiency, officers should give personal attention to the organization and instruction of the radio personnel.

     Inform radio room of ship’s position every hour so that, in case of disaster, a signal may be made promptly.

     Unless provision to the contrary be made operators will work blindly and with imperfect understanding of the operations in hand and of the importance of their part in it. They will transmit and receive coded messages with little idea of their relative importance, except as may be indicated by certain conventional signs, such as the use of the words “Urgent.” “Rush,” etc. Even with the slight knowledge thus conveyed, operators cannot judge of the relative importance of so-called “urgent’ or “Rush” messages from their own and other ships, and interference it he air will frequently be caused by two or more operators attempting to jam through important messages simultaneously.

     In order to overcome the difficulties referred to, and to permit operators to work with the efficiency which will be derived from knowledge the following details of procedure which have been found useful in flotilla work, may be followed when though desirable:

(a) Bridge keep radio room furnished with a correct and comprehensible diagram showing the disposition of convoy and escort, in order that the operators may know the relative position of vessels and their approximate distance from each other.

(b) Impress operators with the importance of their work to the general success of the operation. Teach them the importance of knowing when to keep silent and when to assist by prompt offer to intercept and relay messages.

(c) permit radio operators to be present at conferences of Commanding Officers prior to setting out on escort duty. This will increase their interest in the operation, will give them a clear idea of the proposed plan and will impress them with the importance of their duty.

(d) Always give the radio operator information as to the nature of every message he is called upon to send in the course of an operation. Sometimes if he cannot get the entire message through he will be able to get through enough of it to make it understood, if he himself knows what it is about.

(e) Encourage operators to keep their superiors informed of errors made by other ships. This should not be looked at in the light of “tale bearing,” but as a very essential matter in the interests of increased radio efficiency.

     (j) Internal Dispostions: Lookouts.Every ship in waters frequented by enemy submarines must be considered as being watched and about to become the target for a torpedo. It is important, therefore, to develop “lookouts” to the highest degree of efficiency.

     They should be warmly clad, and not remain on lookout for more than one hour at a time.

     By Day.They must keep a good lookout by day ahead, astern, and on bow, beam, and quarter. A periscope may be sighted 3 feet above the water, or only 6 inches. It may only emerge at intervals. Watch for the “feather” made by the moving periscope. Examine the sea carefully for disturbed water, oils treaks, or swirls.

     Maintain a horizon lookout by day from as high a position as practicable. Unusual smoke or flashes of gunfire may thus be seen, or the sound of guns or bombs may be heard when there is nothing actually in sight.

     A submarine may be disguised with sails—a funnel with smoke coming out, etc.

     By Night.They must keep a good lookout at night for submarines on the surface. They are frequently on the surface for charging batteries. The conning tower may look like a boat or a wrecked charthouse. Anything that is seen may be of importance. It may be a dummy periscope with mine attached; a boat with bombs in it which will explode if salvage is attempted; or it may contain men who are survivors from some torpedoed vessel.

     At night the watch being relieved should no leave station until the eyes of the relief have become accustomed to the darkness.

     Keeping Guns Ready.Be ready at all times with at least one gun in any direction. A submarine may be suddenly sighted at night or in foggy weather. If a submarine is sighted at long range commence firing on the chance that a lucky shot may take effect or injure her sufficiently to prevent diving.

     Running Lights.Keep ship properly darkened but have running lights ready to turn on instantly. All running lights should be arranged to show “dimmed” lights in addition to lights of usual strength. Two lamps one of small voltage for “dimmed” lights, and another for full strenngt, should be provided.

     Searchlights.Do not use searchlights at night unless absolutely necessary. Very’s lights are usually sufficient to illuminate boats or rafts being picked up at night. The lens of searchlight should be covered on moonlight or starlight nights so as not to reflect light. If it becomes necessary to use searchlights cover them with bag after use as carbons glow for an appreciable time after current is turned off.

     Clothing.Crews should be warmly dressed—men have endured many hours of exposure in the water in warm clothing; scantily clad men die soonest of exposure.

     Life Rafts and Boats.Life-saving appliances, rafts, boats, etc., should be so rigged that in case vessel sinks they will easily float clear. Rafts should be disposed at several points of ship instead of being stowed in one locality. Lash provisions, water, etc., to rafts, so that if rafts are capsized, provisions and water will not be lost.

     Fuel.All vessels should be fully fueled and provisioned before leaving port. Escort Commander shall be notified in time for him to take proper action should fuel supply be so reduced as to be likely to prevent any vessel from completing her duty with convoy.

     Boiler Power.Full power shall be available for immediate use when in company with transports.

     Codes.Bear in mind that the enemy is continuously endeavoring to decipher our code messages and the more words he intercepts the better his chance of success. Do not let codes fall into the hands of the enemy. Make all messages as brief as practicable.

     Making General Notes.Make notes on everything new that occurs in every voyage. They prove useful.


     The principal duties of patrols are:

(a) To attack submarines in assigned area.

(b) To protect shipping in assigned area.

     The knowledge of mine fields and probable location of enemy submarines possessed by patrol vessels is always more recent than that possessed by patrol vessels is always more recent than that possessed by merchant ships. Latest information in possession of patrol vessels must always be furnished to all merchant vessels encountered. When a ship is encountered she must be considered as in danger from submarine attack and should therefore be accompanied until clear of the patrol area; or if a valuable ship, until the patrol vessel is relieved by one in an adjacent area.

     It is always assumed that a patrol vessel is on its patrol station and in the area assigned unless report is made of having left it.



     Every opportunity should be taken to conduct war games. A combination of the tactical game with a chart maneuver can easily be carried out aboard ship. Game board maneuvers furnish an excellent means of training in tactical methods as well as of experimenting with them.



     The varied nature of activities involved in the anti-submarine campaign, the varied composition of our forces, and the fact that we are operating under other forces or in conjunction with them, render it very difficult to avoid multiplicity of instructions.

     It is very important, however, that considerable trouble should be taken in keeping records so arranged as to be easy of references and access to all officers.

     On certain destroyers it has been found very useful to file all instructions and intelligence information which is of current importance or interest, in loose-leaf binders kept in locker in Ward Room in which officers, while off watch or duty, have easy access.

WM. S. SIMS,            

Vice-Admiral, U. S. Navy,    


Source Note: Cy, DNA, RG 45, Entry 520, Box 676. These instructions include a set of “Diagrams of Disposition of Escorting Vessels,” which can be found on the August 1918 Illustrations page.

Footnote 2: This document has not been found.

Footnote 3: This was a 1916 manual written by then Lt. Cmdr. William S. Pye. Pye served as Fleet Tactical Officer with the Atlantic Fleet during World War I.

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