Glossary Archive

A tall vertical spar or structure on a sailing vessel that supports the sails, rigging, and sometimes navigation equipment. A mast is one of the most essential components of a sailing vessel, providing the necessary height and support for the sails, which in turn harness the wind to propel the boat forward. Traditionally made from...

A white, forward facing light exhibited near the masthead by a power-driven vessel underway.

Fitting into which the mast heel fits

An internationally recognised distress signal used in voice communication to indicate a grave or imminent, life-threatening emergency at sea. The term "Mayday" is a critical part of maritime communication and one of the pro-words in the Standard Marine Communication Phrases. Originating from the French phrase "m'aider," which means "help me." It is used exclusively in...

The Maritime and Coastguard Agency (MCA) is a UK government agency responsible for implementing maritime safety and environmental policies. It oversees the UK’s search and rescue operations, promotes safety at sea, enforces maritime law, and coordinates responses to pollution incidents. The MCA is part of the Department for Transport. Key Responsibilities of the MCA Search...

The International Maritime Signal Flag Mike. Meaning My vessel is stopped and making no way through the water.

The average height of high tides during neap tide cycles, which occur when the tidal range is at its smallest. Mean High Water Neaps (MHWN) is a concept in tidal studies and marine navigation. It represents the average level reached by high tides during neap tide periods, which occur approximately twice a month when the...

The average height of the high waters that occur during spring tides, calculated over a specific period of time. Mean High Water Springs (MHWS) is a tidal datum used in marine navigation, coastal engineering, and shoreline management. It represents the average level reached by high tides during spring tide conditions, which occur approximately twice a...

The average height of low tides during neap tide cycles, which occur when the tidal range is at its smallest due to the reduced gravitational pull of the sun and moon. Mean Low Water Neaps (MLWN) is a tidal datum used in marine navigation and coastal management to describe the average level of low water...

The average level of the lowest low tides that occur during spring tide conditions, calculated over a standard period of time. Mean Low Water Springs (MLWS) is a tidal datum used in marine navigation, hydrography, and coastal engineering. It represents the average height of the lowest tides that occur during spring tides, which are the...