Glossary Archive

A type of map projection where the surface of the Earth is projected onto a plane from the centre of the globe, causing great circles to appear as straight lines. A gnomonic projection is a method of map-making that projects the surface of a sphere, such as the Earth, onto a flat plane. The projection...

The collective set of systems that enables positioning devices to calculate latitude & longitude. The system includes solutions including the GPS (US) and GLONASS (Russian) network of satellites.

To change tack by altering course to bring the wind on the other side

When going backwards through the water you may hear the skipper say: "I am going astern".

Pronounced: GOLF The term for the letter G in the NATO Phonetic Alphabet.

A pivotal fitting on a sailing vessel that connects the boom to the mast, allowing for controlled movement in multiple directions. The gooseneck is a critical component of a sailboat's rigging system, designed to facilitate the smooth operation of the boom, which is the horizontal spar that extends from the mast and supports the foot...

A sailing configuration where a fore-and-aft rigged vessel's sails are set on opposite sides of the boat, typically with the mainsail on one side and the headsail (like a jib or genoa) on the other, to maximise downwind efficiency. In more detail, the term "goose-winged" describes a specific sail arrangement used when a sailing vessel...

The US-based system of satellites, able to determine the latitude and longitude of a receiver on Earth by calculating the time difference for signals from different satellites to reach the receiver. GPS is part of the GNSS solution for positioning used by chart plotters and other positioning devices.

Rails fitted above and below decks to grab at when the vessel heels

The mean solar time at the Prime Meridian in Greenwich, London, used as a global time standard. Greenwich Mean Time (GMT) is a timekeeping system that started at the Royal Observatory in Greenwich, London, and acts as a reference point for global time zones. It is based on the mean solar time at the Prime...