Glossary
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TermDefinition
- Courses, RYA Marine Radio VHF (SRC)The RYA Marine Radio VHF (SRC) course is a mandatory qualification for anyone operating a marine VHF radio with Digital Selective Calling (DSC).... More Details
- Organisation Maritime and Coastguard Agency (MCA)
The Maritime and Coastguard Agency (MCA) is a UK government agency responsible for implementing maritime safety and environmental policies. It...
More Details - General Nautical Terminology, Safety Maritime Mobile Service Identity (MMSI)
A unique nine-digit number assigned to a vessel, coast station, or group of stations for digital communication and identification in the Global...
More Details - General Nautical Terminology Maritime Rescue Coordination Centre (MRCC)
A shore-based facility responsible for coordinating and managing maritime search and rescue (SAR) operations within a designated area of...
More Details - General Nautical Terminology, Navigation Maritime Safety Information
Defined in the Safety of Life at Sea (SOLAS) Convention, Chapter IV as "navigational and meteorological warnings, meteorological forecasts and...
More Details - General Nautical Terminology MARPOL
Established by the IMO, MARPOL is the convention for preventing pollution from ships. It is the main international convention covering the...
More Details - General Nautical Terminology Mast
A tall vertical spar or structure on a sailing vessel that supports the sails, rigging, and sometimes navigation equipment.
A mast is one of...
More Details - General Nautical Terminology Masthead light
A white, forward facing light exhibited near the masthead by a power-driven vessel underway.
- General Nautical Terminology Mast StepFitting into which the mast heel fits
- General Nautical Terminology, Safety, Signals & Communication MayDay
An internationally recognised distress signal used in voice communication to indicate a grave or imminent, life-threatening emergency at...
More Details - Organisation MCA
The Maritime and Coastguard Agency (MCA) is a UK government agency responsible for implementing maritime safety and environmental policies. It...
More Details - Flag / Pennant, Signals & Communication Code Flag Mike (M)

The International Maritime Signal Flag Mike.
Meaning
My vessel is stopped and making no way through the water.
- Abbreviation, General Nautical Terminology, Navigation Mean High Water Neaps (MHWN)
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...
More Details - Abbreviation, General Nautical Terminology, Navigation Mean High Water Springs (MHWS)
The average height of the high waters that occur during spring tides, calculated over a specific period of time.
Mean High Water Springs...
More Details - Abbreviation, General Nautical Terminology, Navigation Mean Low Water Neaps (MLWN)
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...
More Details - Abbreviation, General Nautical Terminology, Navigation Mean Low Water Springs (MLWS)
The average level of the lowest low tides that occur during spring tide conditions, calculated over a standard period of time.
Mean Low Water...
More Details - General Nautical Terminology, Safety MEDILINK
A communication made via radio from a vessel to a shore-based medical facility or professional to seek urgent medical advice or assistance for an...
More Details - General Nautical Terminology, Signals & Communication Medium Frequency (MF)
The range of radio frequencies between 300 kHz and 3 MHz, commonly used in marine communication and navigation systems.
Medium Frequency (MF)...
More Details - General Nautical Terminology, Organisation, Weather (Meteorology) Met Office
The United Kingdom's national meteorological service, responsible for providing weather and climate-related services, including marine...
More Details - General Nautical Terminology, Signals & Communication MF
The range of radio frequencies between 300 kHz and 3 MHz, commonly used in marine communication and navigation systems.
Medium Frequency (MF)...
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