War Instructions United States Navy 1944
Chapter 3. Bases
Section I. Protection of Naval Units at a Base
301. A campaign may require the establishment of advanced bases. This is accomplished with or without opposition and requires all new facilities or mainly the repair of existing facilities. In any event, the facilities required and the base defense forces have to be transported overseas and established. If practicable, the defense forces follow the assault forces closely. Until such time as the Army can take over the defense of these bases, it devolves upon the Navy. The plans for the establishment of the advanced base designate the Base Commander, indicate when he assumes responsibility for the shore defenses of the base, state what forces are available to him for this purpose, and provide for the relief of Navy or Marine Corps Defense Forces (including air) by the Army if the latter does not originally provide such forces but does do so eventually.
302. When possible a base defense force is organized to man the shore defenses established and to operate the routine patrols and services required. The vessels and aircraft of naval units are organized to assist, if required, in the defense of the base, and plans are prepared to repel all probable forms of attack. If not practicable to organize a base defense force, the senior officer of the vessels occupying the base prescribes the measures to be taken for security while at the base.
(a) Nets and barriers.--Protection of a fleet anchorage is provided by mine fields,
appropriate types of nets and booms, underwater detection apparatus, radar (surface and air
search), and taking full advantage of natural barriers such as shoals which will prevent
enemy vessels from firing torpedoes from outside the barriers into the fleet anchorage area.
Areas of the anchorage which cannot be protected against torpedo fire by natural barriers
are protected by torpedo nets. Heavy ships receive individual protection, particularly
against the various types of torpedoes. At bases where barriers are not under constant
close observation from observation stations, the barriers and area inside the barriers are
patrolled, particularly at night.
(b) Off-shore patrol.--The area outside the barriers is patrolled by surface craft and aircraft. If practicable, the air patrol extends for sufficient distance to sea to give reasonable assurance that enemy forces cannot attack the base before our vessels can get clear of the harbor.
(c) Channels.--If practicable, more than one channel from the anchorage to deep water
is provided. Anchorages at the base are so arranged that vessels have free movement
for entrance and sortie. Approach and entrance channels are swept for mines prior to
entrance of departure of units.
(d) Anchorage.--In general the heaviest ships are anchored furthest from nets or barriers. Repair, fuel, and supply vessels are anchored where they can best be protected from air attack and from gun bombardment from the sea.
(e) Aircraft and aircraft carriers.--If practicable a carrier does not remain at a base with aircraft on deck, unless the base is such that the carrier can get underway without delay to launch aircraft, or unless conditions are such that aircraft can be launched from the carrier while at anchor. It is desirable that facilities be provided for carrier-based planes to operate from shore during the time that the carrier is at the base. The potentialities for effective use of landing fields by carrier air groups are given careful consideration in the planning of carrier operations. As carrier air groups are organized and prepared to operate either from carriers or advanced bases, it is necessary that the latter have adequate trained personnel with suitable facilities.
(f) Antiaircraft defense.--Antiaircraft defense is organized with the greatest care. In addition to the ships' facilities and batteries, it includes, when practicable, shore-based radars, radio direction finders, balloon barrages, and antiaircraft batteries in considerable density. Shore-based defensive fighter planes controlled by a fighter director are also provided, and are probably the most important element of the defense. Rapid means of communication is essential between the Command Post ashore and the Senior Officer Present Afloat. A common warning and information net for ships present and the post ashore is also essential.
(g) Shore defense forces.--Ordinarily the shore defense forces consist of infantry, artillery (light, heavy, and antiaircraft), engineers, and chemical troops. The strength and proportion of the various arms depend upon many factors, but are primarily affected by the naval plan, the importance and probable permanency of the base, its location with respect to hostile territory, its vulnerability to attack and the nature and extent of the area adjacent to and surrounding the base.