AIS

Automatic Identification System — a VHF-based transponder network that continuously broadcasts a vessel's identity, position, course, and speed to other AIS-equipped craft and to shore stations, greatly improving collision awareness.

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Related A-terms

Asymmetric spinnaker

A downwind sail (also called a cruising chute or gennaker) with a fixed tack but no pole, …

Autopilot

An electronic self-steering system that uses a heading or GPS input to drive a hydraulic r…

Adrift

Afloat with no means of propulsion or attachment, carried along by wind, current, or tide.

AIS-MOB

A personal AIS man-overboard beacon that, when activated (usually automatically on immersi…

Aground

The condition of a vessel whose keel or hull is in contact with the seabed.

Amidships

At or toward the middle of the vessel, whether fore-and-aft or athwartships.

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