Glossary Archive

The lowest level that sea tides can reach under normal meteorological conditions, based on astronomical influences such as the gravitational pull of the moon and sun. Lowest Astronomical Tide (LAT) is a tidal datum used as a reference point for charting and navigation. It represents the lowest predicted tide level that can occur due to...

The marker in the compass which is aligned with the fore-and-aft line of the boat against which the course can be read off on the compass card

The leading edge, which is the part of the sail that faces the wind when the sail is set correctly. The luff of a sail is a critical part of sailboat dynamics and sail trim. It is the forward-most edge of the sail, running from the head (top) of the sail down to the tack...

To steer a sailing vessel closer to the wind, reducing the angle between the boat's heading and the direction of the wind.  "Luff up" is a critical manoeuvre in sailing that involves steering the boat closer to the direction from which the wind is blowing, known as "heading up." This action reduces the angle between...

A temporary drop in wind speed

Sea area of the Met Office Shipping Forecast. Lies in the Bristol Channel, around Lundy Island off southwest England. Named for Lundy Island (Norse “Lund-ey,” puffin island), Lundy has southwest winds of Force 5–7 and rough seas. Britain’s first Marine Conservation Zone sees frequent winter gales that test its rugged coastline.

The direction towards the Earth's magnetic north pole, where a compass needle points, which differs from true geographic north. Magnetic North is the point on the Earth's surface where its magnetic field points vertically downwards, and it is the direction that a magnetic compass will indicate. Unlike True North, which is a fixed point at...

A UK government agency responsible for investigating marine accidents and incidents to improve maritime safety. Part of the Department for Transport, the MAIB examines incidents involving UK vessels anywhere in the world and foreign vessels in UK waters. Key Roles and Responsibilities of the MAIB Investigation of Marine Accidents: The MAIB investigates accidents involving all...

Raising sail and getting under way using sail power. This appears to be an unusual or possibly local expression, and may be intended to refer to making sail. It describes the process of hoisting or setting sails so the vessel can begin sailing. The crew prepare halyards, sheets and reefing lines, check the wind direction,...

The principal and typically largest sail on a sailing vessel, attached to the mainmast and used to harness wind power for propulsion. The mainsail is a critical component of a sailing vessel's rigging, as it provides the primary source of propulsion when the boat is under sail. It is typically hoisted on the mainmast, which...