battle cruiser—A large and very powerful fighting ship, of high speed, and with an armament equal or superior to that of a battleship, but very lightly armoured.
beam—The width of a vessel at her widest part.
bearing—The direction, or angular distance from a meridian, in which an object lies.
beat—To beat to windward is to make progress in a sailing vessel in the direction from which the wind is blowing.
belay—To make fast; as, to belay a rope.
belaying pin—A movable pin or bolt of wood or metal to which lines are belayed.
below—To go below is equivalent, on shipboard, to going downstairs.
berth—A bed or bunk on board ship; a place for a ship to tie up or anchor is sometimes called a berth.
between decks or ’tween decks—Any place below the main deck on a ship of more than one deck.
bilge—That part of the hull of a ship inside and adjacent to the keel.