Glossary Archive

The Angle of Vanishing Stability (AVS) refers to the maximum angle at which a vessel can heel (lean to one side) before it loses its ability to return to an upright position. Sometimes referred to as the Vanishing Angle, once the angle of heel exceeds the AVS, the vessel will continue to capsize and may...

Level with the surface of the water which just washes over an object

An inner forestay

Back (backing) describes the wind’s change in direction when it shifts counterclockwise (anti-clockwise). For example, if the wind shifts from north to west to southwest, it is said to be “backing.” This is important for navigation and weather prediction at sea.

To back a sail means to adjust it so that the wind blows on the opposite side from normal, causing the sail to push the boat in the opposite direction. Backing a sail can assist in manoeuvres like tacking, slowing the boat down, or helping steer during tight manoeuvres, such as docking or handling tricky...

The backstay runs from the top of the mast to the stern of the vessel. The backstay supports the mast and in some cases can be adjusted to change the bend in the mast which aids sail trim. On yachts with very large mainsails which would interfere with the backstay, running backstays would be fitted.

To remove water from the bilges or cockpit

A utensil used to bail water out of a boat

A black signal shape displayed when a vessel is at anchor by day

Additional weight placed low in the hull to improve stability