Glossary Archive

A white light displayed by a vessel at anchor to indicate its position to other vessels during the night or in poor visibility conditions. An anchor light is a crucial safety feature for any vessel that is stationary and anchored, particularly at night or in conditions of reduced visibility, such as fog or heavy rain....

A dedicated storage compartment, typically located in the bow of a vessel, used to store the anchor and its associated gear, such as the rode and chain. The anchor locker is an essential feature on most recreational and commercial boats, designed to keep the anchor and its related equipment secure and organised when not in...

A fitting mounted on a boat's bow designed to guide, support, and secure the anchor and its rode during deployment and retrieval. An anchor roller is an essential piece of hardware installed on the bow of a vessel, typically at the stem or near the bow pulpit. It is designed to facilitate the smooth deployment...

The maximum angle of heel at which a vessel can recover to an upright position without capsizing. The Angle of Vanishing Stability (AVS) is a critical measure of a vessel's seaworthiness and stability, particularly in rough seas. It refers to the point at which a vessel, when heeled over by wind, waves, or other forces,...

1. General The lights mentioned herein shall, is exhibited in pursuance of Rule 26 (d), be places where they can best be seen. They shall be at least 0.9 m apart but at a lower level than lights prescribed in Rule 26 (b)(i) and (c)(i). The lights shall be visible all round the horizon at...

1. Whistles Frequencies and range of audibilityThe fundamental frequency of the signal shall lie within the range 70-700 Hz. The range of audibility of the signal from a whistle shall be determined by those frequencies, which may include the fundamental and/or one or more higher frequencies, which lie within the range 180-700Hz (± 1%) for...

1. Definition The term "height above the hull" means height above the uppermost continuous deck. This height shall be measured from the position vertically beneath the location of the light. 2. Vertical positioning and spacing of lights On a power-driven vessel of 20 m of more in length the masthead lights shall be placed as...

1. The following signals, used or exhibited either together or separately, indicate distress and need of assistance: a gun or other explosive signal fired at intervals of about a minute; a continuous sounding with any fog-signalling apparatus; rockets or shells, throwing red stars fired one at a time at short intervals; a signal made by...

Paint applied to hull below waterline to discourage dirt and wildlife attaching and slowing your progress. Has environmental implications

Appraise – To assess the situation, vessel condition, and environmental factors to inform safe navigation decisions. Plan – To develop a detailed course of action for a voyage, considering route, weather, tides, and safety measures. Execute – To carry out the planned voyage or manoeuvre using appropriate seamanship and navigational practices. Monitor – To continuously observe and evaluate the...