Glossary Archive

A type of data format used in oceanography and meteorology to represent gridded data in a binary form for efficient storage and processing. It’s a World Meteorological Organization (WMO) format for packing weather model data (wind, pressure, waves, etc.) into compact binary files. This format involves organising data into a grid structure where each grid...

A general term for the anchors, cables and all the gear required when anchoring

A composite material made of a polymer matrix reinforced with fine glass fibres, commonly used in marine applications for its strength, durability, and resistance to corrosion. Glass Reinforced Plastic (GRP), also known as fibreglass, is a widely used material in the marine industry due to its unique combination of properties. It is created by embedding...

Safety line fitted round the vessel to prevent the crew falling overboard

A safety barrier installed along the edges of a vessel’s deck to prevent crew or passengers from falling overboard. This essential feature on boats and ships usually consists of horizontal wires, ropes, or metal bars supported by stanchions along the deck’s perimeter. Its main purpose is to provide a physical barrier that helps prevent accidental...

The upper edge or rim of a boat's side, often serving as a structural reinforcement and a mounting point for fittings or equipment. The term "gunwale" (pronounced "gunnel") originates from the days of sailing ships when this part of the vessel was reinforced to support the weight and recoil of mounted guns or cannons. Today,...

A rope, wire, or chain used to stabilise or secure a mast, spar, or other structure on a vessel by counteracting lateral forces. A guy is a critical component in the rigging of a ship or sailboat, designed to provide stability and control to masts, spars, and other vertical or angled structures. In maritime contexts,...

A gybe (jibe) is a sailing manoeuvre where a boat changes direction by turning its stern through the wind. During a gybe, the wind crosses over the stern of the boat, causing the sails to shift from one side to the other. This manoeuvre is often used when sailing downwind or changing course in a...

The call to indicate that the helm is being put across to gybe

A line or rope used to hoist or lower a sail, flag, or spar on a boat. The term "halyard" comes from the phrase "haul yard," which refers to the action of raising the yard in a sailing vessel. Halyards are essential components of a sailboat's rigging system, as they allow sailors to raise and...