Glossary Archive

A unit of distance traditionally used to measure short distances at sea. It is generally considered one-tenth of a nautical mile, which equals approximately 185.2 meters or 100 fathoms. The length of a cable can vary depending on the standard used. In the British Navy, a cable is traditionally defined as 1/10th of a nautical...

A strong, heavy rope or wire, often made of steel, used for mooring, anchoring, or towing vessels. A cable refers to a thick, durable line, traditionally made from natural fibres like hemp but now more commonly constructed from steel or synthetic materials. Cables are essential in various operations aboard ships, including anchoring, mooring, and towing....

The CADET mnemonic can help remember the corrections needed when converting between True North and Compass North bearings. It assists in adjusting for magnetic variation and deviation, which is essential for accurate navigation. Here’s what each letter in CADET represents: CADET Mnemonic Breakdown C — Compass: Start with the compass bearing, the direction the compass...

A unique identifier assigned to a vessel or maritime station for communication purposes, typically used in radio transmissions. A call sign is a critical component of maritime communication, serving as a vessel's unique identifier when transmitting over radio frequencies. National or international regulatory bodies, such as the International Telecommunication Union (ITU), assign these identifiers. They...

A mechanical device with spring-loaded, opposing cams that grip a rope or line to hold it securely while allowing for quick adjustments.  A cam cleat consists of two spring-loaded, serrated cams that rotate inward to grip a line when it is pulled taut. The design allows for easy engagement and release by simply pulling or...

Cancel (or Disregard) informs the receiver to disregard the previous message or cancel the signalling. There is no specific attachment to this signal, so context and some interpretation will be required unless the sender specifics by spelling out the cancel message.

An overturning of a boat so that the hull or keel becomes exposed. This can happen when a small craft is overpowered by wind, hit by a wave, loaded unevenly, or handled in a way that reduces stability. Dinghies are designed to be recovered after this happens, but larger vessels may be in serious difficulty...

Cardinal Bearings are the main points on a compass, expressed by their name. There are four main cardinal points, North, South, East, and West which are also known by their first letters: N, S, E, and W. There are also four cardinal half points between each main cardinal point: North East, South East, South West,...

Buoy or pillar placed North, East, South or West side of an obstruction to warn vessels away. Cardinal marks indicate that the deepest water in the area lies to the named side of the mark. They are used in conjunction with the compass to indicate the direction from the mark in which the deepest navigable...

Releasing a rope or line so a vessel can move away. This is commonly used when leaving a berth, buoy, tow or alongside position. Lines should be released in the right order for the wind, tide and intended departure plan. A line may still be under load, so it should be eased or slipped rather...