ACKER. _See_ EAGRE or AIGRE. Also, an eddying ripple on the surface of flooded waters. A tide swelling above another tide, as in the Severn. (_See_ BORE.) ACK-MEN, OR ACK-PIRATES. Fresh-water thieves; those who steal on navigable rivers. A-COCKBILL (_see_ COCK-BILL). The anchor hangs by its ring at the cat-head, in a position for dropping. ACOLYTE. A term sometimes used to distinguish the smaller component of a double star. A subordinate officer in the ancient church. ACON. A flat-bottomed Mediterranean boat or lump, for carrying cargoes over shoals. ACQUITTANCE. A commercial term, more generally called _quittance_ (which see). ACRE, OR ACRE-FIGHT. An old duel fought by warriors between the frontiers of England and Scotland, with sword and lance. This duelling was also called _camp-fight_. ACROSS THE TIDE. A ship riding across tide, with the wind in the direction of the tide, would tend to leeward of her anchor; but with a weather tide, or that running against the wind, if the tide be strong, would tend to windward. A ship under sail should prefer the tack that stems the tide, with the wind _across the stream_, when the anchor is let go. ACROSTOLIUM. A buckler, helmet, or other symbolical ornament on the prow of ancient ships; the origin of the modern figure-head. ACT AND INTENTION. Must be united in admiralty law. ACTE. A peninsula; the term was particularly applied by the ancients to the sea-coast around Mount Athos. ACT OF COURT. The decision of the court or judge on the verdict, or the overruling of the court on a point of law. ACT OF GOD. This comprehends all sudden accidents arising from physical causes, as distinguished from _human_ agency, such as from lightning, earthquakes, hurricanes, plagues, and epidemic contagion amongst the crew. For none of these are ship-owners responsible. ACT OF GRACE. An act of parliament for a general and free pardon to deserters from the service and others. ACTING COMMISSION. When a commissioned officer is invalided, his vacancy is filled up pending the pleasure of the admiralty by an acting order. But when an officer dies on a station, where the admiralty delegates the power to the admiral commanding in chief, the vacancy is filled by an acting commission. Thus also rear-admirals now act on acting commissions as vice-admirals during command on their station, but return to their proper position on the navy list when it ceases. ACTION. Synonymous with _battle_. Also a term in mechanics for the effort which one body exerts against another, or the effects resulting therefrom.--_Action and reaction_, the mutual, successive, contrary impulses of two bodies. ACTIVE SERVICE. Duty against an enemy; operations in his presence. Or in the present day it denotes serving on full-pay, on the active list, in contradistinction to those who are virtually retired, and placed on separate lists.