Glossary Archive

A light where there is more darkness than light

This shape represents the Letter F (Flag Semaphore) and the Number 6 (Flag Semaphore).

International Morse Code sequence representing the letter F.

The incoming or rising phase of the tide, during which seawater flows landward and the water level increases.  A flood tide is the period during the tidal cycle when the sea level rises due to the Moon's and Sun's gravitational pull, causing water to flow from the open ocean towards the shore. This phase occurs between low...

The flat, triangular blade or arm of an anchor designed to dig into the seabed and provide holding power. The term "fluke" in a marine context primarily refers to the pointed, flat parts of an anchor that are responsible for securing the vessel to the seabed. Flukes are engineered to penetrate and grip various types...

The rapid and uncontrolled movement of a sail or line due to a sudden change in wind or tension. Flying out typically describes an event where a sail, sheet, or other rigging component is suddenly released or becomes loose, causing it to flap or move uncontrollably in the wind. This can happen when a line...

A method of encoding information in a carrier wave by varying its frequency, commonly used in marine radio communications. Frequency modulation (FM) is a technique used to transmit information over radio waves by varying the frequency of the carrier signal in proportion to the amplitude of the input signal, which typically contains voice or data....

The part of the accommodation below the foredeck and forward of the mast

Visibility reduced to less than 1000 metres (approximately 0.5 nautical miles)

Fog horns are used for sounding the appropriate sound signal whilst in restricted visibility