Block

The marine term for a pulley — a sheave in a housing through which a line runs.

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Related B-terms

Barometer

A pressure-measuring instrument whose readings are used to monitor and predict weather tre…

Boat hook

A shaft with a hook and a blunt end, used for snagging mooring lines, retrieving overboard…

Burdened vessel

The former term (replaced in modern COLREGs usage by 'give-way vessel') for the vessel obl…

Boat speed

The speed at which the hull moves through the water, as opposed to speed over ground.

Beating

Working to windward by sailing a succession of close-hauled tacks.

Bottom

The underwater surface of the hull.

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