Glossary Archive

Short choppy seas

A highly accurate timekeeping instrument, specifically designed for determining longitude at sea. A chronometer is a precision timepiece used aboard ships to aid in navigation by providing an accurate measure of time, which is crucial for determining a vessel's longitude. Before the invention of the marine chronometer in the 18th century, sailors had no reliable...

⚓ 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 than just cargo—they might also bring diseases like cholera, plague, or yellow fever. To prevent outbreaks, port authorities began requiring ships to present a “bill of health”—an official document from the last port of...

Clear water is transparent and free from sediment, debris, or other particles that may obstruct visibility. This is important for snorkelling, diving, or fishing, where clear water allows for better visibility of marine life and surroundings.

Clear weather refers to atmospheric conditions free of significant cloud cover, precipitation, fog, or other weather disturbances. The sky is typically sunny or mostly sunny in clear weather, allowing for good visibility and pleasant outdoor conditions.

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 practice to give the instruction 'Clear', indicating that the line is free from its attachment and out of the water. This avoids potential entanglement in the vessel's propeller and informs...

The distance between top of mast and bridge or bottom of keel and seabed.

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 looped around them to provide a secure attachment point. Cleats are commonly used for tying off dock lines, anchor lines, and other ropes on a boat.

This shape represents the Letter C (Flag Semaphore) and the Number 3 (Flag Semaphore).

International Morse Code sequence representing the letter C.