Galvanic isolator

A device fitted in the shore-power earth conductor to block low-voltage galvanic currents that would otherwise corrode underwater metals while connected to a marina.

Test your knowledge

Know your nautical terms? Play the free SkipperCheck daily maritime quiz — COLREGs, navigation, VHF radio, seamanship. Earn points, climb the global leaderboard.

Play the Daily Quiz →

Related G-terms

GNSS

Global Navigation Satellite System — the umbrella term covering all satellite positioning …

Great Circle

The shortest path between two points on the Earth's surface — an arc of a circle whose pla…

GRIB file

A compact binary weather-data format (Gridded Binary) used to download forecast wind, pres…

Genoa

A large headsail whose clew overlaps the mast, giving extra upwind drive compared with a w…

Gudgeon

A ring-shaped fitting on the transom into which a rudder's pintle pin drops, allowing the …

G.M.T.

Greenwich Mean Time — the mean solar time at the prime meridian in Greenwich, London. Now …

← Back to full glossary