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A/c aircraft
Aback Said of a sail when, with its clew to winward, is pressed back towards the mast. It may happen due to a sudden change of wind.
aback Wind on the wrong side of the sails.
ABAFT Toward the rear (stern) of the boat. Behind.
Abaft Toward the rear of the boat, behind the boat.
Abeam At right angles to the center of the boat
Able bodied seamen A member of the deck crew who is able to perform all the duties of an experienced seamen; certificated by examination; must have three years sea service. Also called Able Seamen and A.B
ABLE SEAMEN (AB) Stand watch, during which they steer the vessel, stand lookout, assist the mate on watch and make rounds of the ship to insure that all is in order. They also tie up and untie the vessel to and from the dock and maintain the equipment on deck.
Aboard On or within the boat
Above deck On the deck (not over it - see ALOFT)
Above Deck: On the deck.
Abreast ff the side, even with the boat.
Abs American Bureau of Shipping: A U.S.-based private classification, or standards setting society for merchant ships and other marine systems
ABS American Bureau of Shipping (classification society)
Abutment: A wall that touches at one side as a low wall at the edge of a bridge.
Abyss: That volume of ocean lying below 300 fathoms from surface.
Aco aircraft coordinator A person who co-ordinates the involvement of multiple aircraft in SAR operations.
admiralty law the "law of the sea."
Adrift Loose, not on moorings or towline
Aframax tanker < 80,000 dwt (average freight rate assessment)
AFT Toward the stern of the boat.
Aft(Or after.) Near, toward or at the stern of a ship
Aft, After Toward the stern (rear) of the boat.
Aftercabin In a ship with multiple cabins, the cabin closest to the stern
Aftermast In a sailing ship carrying multiple masts, the mast set closest to the stern. Also called the mizzenmast in a three- masted sailing vessel
Aftermost The farthest aft
Against the Sun: Anti-clockwise circular motion. Left-handed ropes are coiled down in this way.
Agency fee A fee charged to the ship by the ship's agent, representing payment for services while the ship was in port. Sometimes called attendance fee
Aground When a boat is in water too shallow for it to float in, i.e: the boatís bottom is resting on the ground.
Ahead In a forward direction
Ahull A boat lies ahull when it is drifting with no sails set
Aid to navigation Any fixed object that a navigator may use to find his position, such as permanent land or sea markers, buoys, radio beacons, and lighthouses.
Aims American Institute of Merchant Shipping
Air Draft: This is the height of a vessel above the water level; including any cargo or mast's. (See also Draft & Bridge hole)
AIS automatic identification system
Alee The side away from the direction of the wind
All Hands The entire crew
Alluvium: Deposits of mud and sand.
ALOFT Above the deck of the boat.
Alongside: Close beside a ship, wharf or jetty.
Altar: Step in a dry dock, on which lower ends of shores rest.
Am amplitude modulation
Amass The outboard hulls of a trimaran.
Amidships In the center of the boat.
AMNI Associate Member of The Nautical Institute
Amok: Homicidal frenzy that sometimes affects Malayans and other eastern peoples.
AMVER US Coast Guard's Automated Mutual-Assistance Vessel Rescue System
Anchor A heavy metal implement used to secure a vessel by lowering in the water to the bottom
Anchor 1) A heavy metal object designed such that its weight and shape will help to hold a boat in its position when lowered to the sea bottom on a rode or chain.
anchor chain A chain attached to the anchor. The chain acts partially as a weight to keep the anchor lying next to the ground so that it can dig in better. Chain is also not damaged as much as line when lying on rocks. The weight of the chain also helps to absorb changes in the boat's position due to waves.
Anchor Ice: Ice, of any form, that is aground in the sea.
anchor light A white light, usually on the masthead, visible from all directions, used when anchored.
anchor locker A locker used to store the anchor rode and anchor.
anchor roller Also called bow roller. A fitting with a small wheel that allows the anchor and chain to roll over when dropping or raising the anchor. Some anchor rollers also have a provision to store the anchor.
anchor windlass A windlass used to assist when raising the anchor.
Anchorage A place where a boat anchors, usually an established and marked area.
Anemometer Instrument for measuring and indicating the speed of the wind
Apeak: Said of anchor when cable is taut and vertical.
API American Petroleum Industry
Apparent Wind The wind that flows over a moving boat
Aqueduct: A bridge that carries a waterway over a road, railway, valley.
Arch A curved architectural structure used to support suspended weight. In Great Lakes wooden shipbuilding, a wide iron- or steel-fastened strap down each side of a ship
Arch board An arch-shaped nameboard fastened to the stern of a ship, displaying the vessel's name and home port
ARCS Admiralty Raster Chart Service
ARPA Automatic Radar Plotting Aids
Articles of agreement The document containing all particulars relating to the terms of agreement between the Master of the vessel and the crew. Sometimes called ship's articles, shipping articles
Aspect Ratio The ratio between the foot length and the luff length of a sail
A-stay: Said of anchor cable when its line of lead approximates a continuation of line of fore stay.
Astern In back of the boat, opposite of ahead
Astern Behind the boat
At sea In marine insurance this phrase applies to a ship which is free from its moorings and ready to sail
Atc air traffic control
Athwart ships: At right angles to the center line of the boat, across the boat from side to side. Also the term given to rowing boat seats.
Athwart, Athwartships Lying along the shipís width, at right angles to the vesselís centerline.
A-trip: Said of anchor immediately it is broken out of the ground.
Ats air traffic services
Automatic pilot An instrument designed to control automatically a vessel's steering gear so that she follows a pre-determined track through the water
Autopilot Electro-mechanical steering device
Auxiliary A second method of propelling a vessel. On a sailboat this could be an engine.
Avast: Order to stop, or desist from, an action.
Aweigh Describes an anchor raised from the seabed