Glossary
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TermDefinition
- Abbreviation, General Nautical Terminology Restricted in Ability to Manoeuvre (RAM)
A ship that, due to the nature of its work, is unable to keep out of the way of other vessels as required by the International Regulations for...
More Details - General Nautical Terminology Restricted Visibility
Conditions in which a vessel's ability to see is significantly reduced due to environmental factors such as fog, heavy rain, snow, or...
More Details - General Nautical Terminology Rhumb LineA line on the surface of the earth that cuts all meridians at the same angle. On a standard Mercator chart the rhumb line appears as a straight line
- General Nautical Terminology Riding Turn
A loop of rope that crosses over itself on a winch drum or cleat, often causing friction or jamming.
A riding turn is a term commonly used in...
More Details - General Nautical Terminology Rigging
The system of ropes, cables, chains, and other apparatus used to support and control the sails and masts of a sailing vessel.
Rigging is...
More Details - General Nautical Terminology Rigging
Verb - The process of setting up and adjusting the sails, lines, and other necessary equipment on a boat or ship to ensure it is ready for...
More Details - General Nautical Terminology Rigid Inflatable BoatA vessel that has both a solid part and inflatable part to its structure
- Organisation RINA
An internationally renowned professional institution representing naval architects and marine engineers worldwide. It was founded in 1860 and is...
More Details - General Nautical Terminology Risk of Collision
The possibility that a collision may occur, usually established by taking a compass bearing of an approaching vessel. Defined in Rule 7 - Risk of...
More Details - Flag Semaphore, Signals & Communication Letter R (Flag Semaphore)

Flag semaphore indicating the letter R.
- Morse Code, Signals & Communication Letter R (Morse Code)
International Morse Code sequence representing the letter R.
- Organisation RNLI
The volunteer crewed rescue service providing 24-hour rescue services around the UK and Irish coastline. They also provide seasonal lifeguards...
More Details - General Nautical Terminology, Weather (Meteorology) Rockall
Sea area of the Met Office Shipping Forecast. Spans the North Atlantic west of Ireland around Rockall islet.
Named for the remote granite islet...
More Details - General Nautical Terminology, Parts of a Boat Rode
The line, chain, or cable that connects an anchor to a vessel.
Rode refers to the length of chain, rope, or a combination of both that...
More Details - General Nautical Terminology Roller Furling
Roller furling is used on sailing boats to roll or unroll a sail, typically the jib or genoa, around a stay to quickly deploy or stow the...
More Details - General Nautical Terminology Roller Reef
A roller reef is a method of reducing sail area on a sailboat by partially rolling or furling the sail around the boom or the headstay. This...
More Details - Phonetic Alphabet, Signals & Communication Romeo
Pronounced: ROW-me-oh
The term for the letter R in the NATO Phonetic Alphabet.
- General Nautical Terminology Round UpTo head up into the wind
- General Nautical Terminology Roving Fender
A spare fender, held ready by a crew member in case of emergencies.
A roving fender is a type of fender used on boats and ships to protect the...
More Details - Organisation Royal National Lifeboat Institution (RNLI)
The volunteer crewed rescue service providing 24-hour rescue services around the UK and Irish coastline. They also provide seasonal lifeguards...
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