Glossary

A location where tidal information is derived by applying corrections to data from a nearby Standard Port. 

A secondary port is a coastal...

Substitute or repeater flags allow messages with duplicate characters to be signalled without requiring multiple sets of flags.

Occasionally a light may not be visible through 360 degrees, or it may shine different colours depending on where it is viewed from. In this...

A maritime safety message broadcast over radio to convey important but non-urgent navigational or weather-related information.

Sécurité is a...

A signalling system used to convey information at a distance by means of visual signals, typically using flags or lights.

Semaphore is a...

A type of boat or ship designed to operate efficiently in both displacement and planing modes, offering a balance between speed and fuel...

The upward movement of water or swell against a fixed object or shoreline.

This is often noticed where waves lift against a harbour wall,...

The direction which a current flows in a body of water.

In marine navigation, understanding the set of a current is crucial for plotting an...

The process of securing a boat in a stationary position by deploying and embedding an anchor into the seabed.

When a mariner 'sets anchor',...

To begin a voyage or journey by sea, typically by hoisting the sails of a sailboat or ship to catch the wind and propel the vessel...

A U-shaped metal fitting with a pin or bolt across the opening, used in marine applications to connect ropes, chains, or other fittings...

Shaft drive refers to a method of transferring power from an engine to a boat's propeller. In this system, a driveshaft connects the engine to...

The part of an anchor that digs into the seabed to secure the boat in place. 

The Shank refers to the long, vertical part of an anchor that...

Sea area of the Met Office Shipping Forecast. Lies off the west coast of Ireland at the mouth of the River Shannon.

From the Shannon Estuary...

A line or rope used to control the angle of a sail relative to the wind.

In sailing, a sheet is an essential part of the rigging system and...

A maritime weather broadcast provided by the UK Met Office, offering vital information on sea conditions, wind, and visibility for seafarers in...

A designated route in a body of water that is regularly used by commercial and cargo vessels to ensure safe and efficient maritime...