Aft: toward, or in, the stern of a vessel. Astern: behind a vessel. Ballast: any heavy substance used to maintain a vessel at its proper draft or trim, or its stability. Beam: the breadth of a ship at its widest part. Beam ends: a ship lying so far over on its side that the ends of her beams are touching the water and she is in danger of capsizing. Beat to quarters: a marine drummer calling a crew to its battle stations. Beat up: to sail in the direction from which the wind is coming. Bilge: the lowest point of the hull, usually containing foul water. Binnacle: box on the quarterdeck near the helm that houses the compass and has drawers where telescopes are kept. Boom: a long spar used to extend the foot (or bottom) of a specific sail. Bomb vessel: a small ketch used to hold mortars for hurling bombs. Bow: the forward part of a ship. Bow chasers: long guns placed on both sides of the bow to allow firing ahead. Bower: large anchor placed at the bows of a ship. Bowsprit: a spar extending forward from the bow or stem of a ship to carry a sail forward and to support the masts by stays.
