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.

Changing tack by turning the bow through the wind. This manoeuvre brings the wind from one side of the vessel to the other, allowing progress to windward in a zigzag pattern. The helm turns the boat through the wind while the crew release and trim the sails on the new side. Timing matters, because the...

Moving backwards through the water under engine or controlled momentum. This is usually done when leaving a berth, stopping a vessel, or controlling position in a tight space. On many vessels the stern will not simply move straight back, because propeller effect, wind and tidal stream can push the bow or stern to one side....

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.

A portable, easily accessible bag containing essential safety and survival equipment needed in an emergency situation at sea. A Grab Bag, also known as a ditch bag, abandon ship bag, or survival bag, is a vital piece of equipment for any boating or sailing trip. Its purpose is to contain all the necessary items that...

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