Glossary Archive

A type of watercraft designed to move through the water by displacing an amount of water equal to its own weight, relying on buoyancy and hydrodynamic efficiency rather than planing. A displacement vessel operates on the principle of Archimedes' buoyancy, meaning it displaces a volume of water equivalent to its weight to remain afloat. Unlike...

The length of space between two points, often measured in nautical miles when referring to distances at sea. In maritime contexts, "distance" refers to the measurement of space between two locations, typically expressed in nautical miles. A nautical mile is slightly longer than a standard mile, equating to approximately 1.1508 statute miles or 1.852 kilometres....

The measured distance, typically in nautical miles, between a vessel's current position and a predetermined navigational point or waypoint. The term "Distance to Waypoint" is a fundamental concept in marine navigation, particularly in the context of electronic navigation systems such as GPS or chartplotters. A waypoint is a specific location marked on a nautical chart...

A navigational tool consisting of two hinged legs with pointed ends, used by mariners to measure distances on a nautical chart. Dividers are an essential instrument in traditional marine navigation, particularly when working with paper nautical charts. They are typically constructed from durable materials such as brass or stainless steel to withstand the harsh marine...

This shape represents the Letter D (Flag Semaphore) and the Number 4 (Flag Semaphore).

International Morse Code sequence representing the letter D.

Screen fitted to give the crew protection from wind and spray

Sea area of the Met Office Shipping Forecast. Spans Dogger Bank in the central North Sea, between the UK and continental Europe. Named after Dogger Bank (from Dutch “doggerschepen,” medieval fishing boats), Dogger is one of the North Sea’s stormiest banks, with frequent winter gales at Force 8–9, rough seas and poor visibility. It was...

A shortened watch period aboard a vessel, typically divided into two shifts from 16:00 to 18:00 and 18:00 to 20:00, to allow for a rotation of watch schedules.  The dog watch is a unique division of the ship's watch system, designed to ensure that crew members do not stand the same watch every day. By...

A mooring post or group of piles