Glossary Archive

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 onboard medical emergency. A Radio Medical Advice Link Call is an essential protocol in maritime operations, particularly for vessels operating far from shore where immediate access to medical facilities is unavailable....

The range of radio frequencies between 300 kHz and 3 MHz, commonly used in marine communication and navigation systems. Medium Frequency (MF) is a segment of the radio spectrum that plays a pivotal role in maritime operations. Falling between 300 kHz and 3 MHz, this range is particularly significant for its ability to propagate over...

The United Kingdom's national meteorological service, responsible for providing weather and climate-related services, including marine forecasts. The Met Office, short for the Meteorological Office, is the UK's official authority for weather and climate science. It plays a vital role in marine operations by issuing forecasts, warnings, and real-time data for coastal and offshore waters. Mariners...

The range of radio frequencies between 300 kHz and 3 MHz, commonly used in marine communication and navigation systems. Medium Frequency (MF) is a segment of the radio spectrum that plays a pivotal role in maritime operations. Falling between 300 kHz and 3 MHz, this range is particularly significant for its ability to propagate over...

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...

Pronounced: MIKE The term for the letter M in the NATO Phonetic Alphabet.

Visibility reduced to between 0.5 and 2 nautical miles due to suspension of water particles in the air

A strong, cold, and dry northwesterly katabatic wind that blows from southern France into the Mediterranean, particularly affecting the Gulf of Lion. The Mistral is a prominent meteorological phenomenon in the northwestern Mediterranean, especially along the southern coast of France. It originates from high-pressure systems over the Atlantic or northern Europe and low-pressure systems over...

Mast aft of the mainmast, on a ship.