Glossary
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TermDefinition
- Phonetic Alphabet, Signals & Communication Charlie
Pronounced: CHAR-lee
The term for the letter C in the NATO Phonetic Alphabet.
- General Nautical Terminology, Navigation Chart
A detailed map used in marine navigation, showing water depths, hazards, and other critical information for safe passage.

A marine chart...
More Details - General Nautical Terminology Chart DatumReference level on charts and for use in tidal predictions. It is approximately the lowest the tide is ever expected to fall because of... More Details
- General Nautical Terminology Charted DepthThe depths shown on the chart are the depths of the seabed below Chart Datum and are therefore the least depth expected at that point in normal... More Details
- General Nautical Terminology Chart Plotter
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An electronic navigation device used on boats to display electronic navigation charts and track the vessel's position in real-time using GPS... - General Nautical Terminology Chart Table
A flat, dedicated surface aboard a vessel used for spreading out nautical charts and plotting courses during navigation.
A chart table is an...
More Details - General Nautical Terminology Chief Mate
The second-in-command on a vessel, responsible for overseeing the ship's day-to-day operations, cargo handling, and the safety of the crew and...
More Details - General Nautical Terminology Chine
The sharp angle or edge formed where the hull's sides meet its bottom, commonly found in hard-chined boats.
A chine is a critical structural...
More Details - Did you know?, Nautical Saying Chock-a-block
Chock-a-block is a nautical term describing when two blocks (pulleys) are pulled so close together that they cannot be tightened further. It...
More Details - General Nautical Terminology ChopShort choppy seas
- General Nautical Terminology, Navigation Chronometer
A highly accurate timekeeping instrument, specifically designed for determining longitude at sea.
A chronometer is a precision timepiece used...
More Details - Did you know?, Nautical Saying Clean Bill of Health
⚓ Nautical Origin of A Clean Bill of Health:
Back in the 18th and 19th centuries, when ships traveled from port to port, they could carry more...
More Details - General Nautical Terminology Clear
Clear water is transparent and free from sediment, debris, or other particles that may obstruct visibility. This is important for snorkelling,...
More Details - General Nautical Terminology Clear
Clear weather refers to atmospheric conditions free of significant cloud cover, precipitation, fog, or other weather disturbances. The sky is...
More Details - General Nautical Terminology Clear
To disentangle a line, for example, removing it from a dock cleat when manoeuvring out of a marina.
When departing from a mooring, it is good...
More Details - General Nautical Terminology ClearanceThe distance between top of mast and bridge or bottom of keel and seabed.
- General Nautical Terminology Cleat
A fitting on a boat or dock used to secure lines or ropes. Cleats typically have two horns or arms extending from a base, allowing lines to be...
More Details - Flag Semaphore, Signals & Communication Letter C (Flag Semaphore)

This shape represents the Letter C (Flag Semaphore) and the Number 3 (Flag Semaphore).
- Morse Code, Signals & Communication Letter C (Morse Code)
International Morse Code sequence representing the letter C.
- General Nautical Terminology, Parts of a Boat Clew
The lower aft corner of a sail, where the foot and leech meet, and is often equipped with a grommet or cringle for attaching control lines such...
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