Glossary

An enclosed compartment aboard a vessel used for accommodation, work or another assigned purpose.

A cabin may be a sleeping space for crew or...

A heavy rope, wire rope or chain used for anchoring, mooring, towing or other load-bearing service.

In traditional and regulatory language, an...

A traditional short-distance unit at sea, now commonly treated as one-tenth of a nautical mile.

Using the international nautical mile, one...

A mnemonic stating that easterly compass error is added when converting a compass direction towards true.

“Compass Add East for True” forms...

An assigned sequence of letters or letters and figures used to identify a radio station or vessel in communications.

For ships, the call sign...

A line-holding fitting with opposed spring-loaded cams whose teeth grip a rope pulled between them.

The line is normally engaged by pulling it...

A semaphore procedural signal instructing the receiver to disregard the preceding transmission or identified part of it.

It is used when...

A principal standing-rigging shroud running from the mast or masthead to the chainplate, commonly over spreader tips.

It provides major...

To overturn a vessel beyond its normal stable operating attitude, potentially onto its side or fully inverted.

Capsize can result from...

The procedure used to right a capsized craft and return it to a safe, controllable condition.

Methods depend on craft design, crew numbers and...

A bearing expressed by a named cardinal or intercardinal direction rather than by degrees.

The four cardinal directions are north, east, south...

An aid to navigation indicating that the named side of the mark is the side on which to pass or find the safest water.

North, east, south and...

The restraint of cargo so it cannot shift, tip, roll or break free during a voyage.

Securing arrangements account for vessel accelerations,...

A radio-frequency wave that is varied to convey information.

Voice, data or signalling modulates one or more properties of the carrier, such...

To release a mooring, towing or other securing line from its fitting.

The expression is commonly used when a vessel leaves a berth, buoy,...

A multihull vessel with two hulls connected by crossbeams, a bridge structure or a deck.

Catamarans may be sail- or power-driven and range...

The hanging curve formed by a flexible line or chain under its own weight between supported points.

In an anchor or mooring system, catenary...

The formation and collapse of vapour cavities where local water pressure falls below the liquid's vapour pressure.

It can occur around...

A power-driven vessel severely restricted in its ability to leave its course because of its draught in relation to the available navigable...

A collision-warning condition in which another object's bearing remains nearly steady while its distance decreases.

If two vessels continue...