Autopilot

An electronic self-steering system that uses a heading or GPS input to drive a hydraulic ram, linear drive, or wheel motor, holding the boat on course without a human helm.

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Related A-terms

Aground

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

Asymmetric spinnaker

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

AIS

Automatic Identification System — a VHF-based transponder network that continuously broadc…

ARPA

Automatic Radar Plotting Aid — radar software that tracks targets automatically and comput…

Aboard

On, onto, or inside the vessel.

Aback

A sail that has been trimmed so the wind pushes against the reverse side of the cloth, fil…

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