The look-outs, increased and cautioned to greater vigilance, relieved at least hourly, and visited by either the Commander or Executive Officer half hourly.
363. The safety of small vessels at night requires that they shall be always either underway, or else in readiness to be got so at the shortest warning.
364. If circumstances prevent this, the greater the necessity for increased precaution and vigilance, and therefore a picket or advice boat should be kept out in the direction from which attack may be expected; and, indeed, the resort of picket-boats should be observed whenever practicable and at all likely to be of service.
365. In case of sending away a boat that is to return before sunrise—which is always to be avoided, if possible—a concerted signal, such as a certain number of flashes of a light, preceded or followed by the firing of a certain number of muskets, must be made at the distance from the vessel of about one-half mile, the number to be agreed upon for each night as the boat leaves the vessel. A countersign is also to be given; but if not understood by the look-out, he is to call out "Enemy," at the same time warning the boat to keep off, at which the vessel will be got underway at once.
366. The boat must be furnished with suitable and reliable fireworks or other means for announcing instantly the approach of an enemy, and no excuse can be taken for a failure on the part of the picket to give the alarm. The capture of the picket-boat is a minor consideration.
367. When confident of being able to repel any force, the boat should return to give timely notice for preparation; and in this case it may be expedient to be prepared to light up the adjacent waters, to enable an effective fire to be opened on the enemy from guns and howitzers.
368. Commanding Officers of vessels situated as described in Art. 359, are required to practise their crews, by going on deck and hailing, "Boat ahoy," at least once a week.
The time taken for the execution of this order to be noted on the log.
369. In times of anticipated attack from rams or mail-clad vessels upon a fleet or single ship, it is recommended to load the guns with maximum charges and solid shot; but where there is doubt of the character of the assailant, the guns should only be loaded with the service powder charge having ready at hand shot, shell, shrapnell, grape, or canister, as the case may demand.