Glossary

An unmanned, self-propelled submersible that carries out a programmed mission without a continuous control link.

An AUV uses onboard...

An automatic steering system that controls a vessel’s rudder or steering mechanism to maintain a selected heading or course reference.

An unmanned, self-propelled submersible that carries out a programmed mission without a continuous control link.

An AUV uses onboard...

A secondary machine, system or service that supports a vessel’s primary operation.

On a sailing vessel, “the auxiliary” commonly means an...

The heel angle at which a vessel's righting lever reduces to zero after its initial range of positive stability.

Before the AVS, the intact...

At or just below the water surface, so that water washes over the object or feature.

The term may describe a low deck or a natural feature...

A short inner forestay that supports the forward part of a sailing vessel’s mast.

A baby stay normally runs from a point on the forward face...

To trim or hold a sail so the wind presses on the side opposite its normal driving side.

A backed headsail can push the bow away from the wind...

A headsail held or sheeted to windward so its aerodynamic force acts opposite to its usual direction.

It is used during heaving-to, some...

Standing rigging leading aft from a mast to support it against forward loads.

A permanent backstay commonly leads from or near the masthead to...

For the wind direction to change anticlockwise when viewed on a compass.

For example, a change from north through northwest towards west is...

To remove water from inside a boat using a bucket, scoop or similar container.

Bailing is common in dinghies, tenders and open boats after...

A container or fitted device used to remove water from a boat.

A hand bailer may be a purpose-made scoop, bucket or other suitable container....

A named sea area used in the UK Shipping Forecast, in the North Atlantic between Scotland and Iceland.

The area takes its name from a sandbank...

Weight carried or built into a vessel to improve stability, trim or draught.

Ballast may be fixed, as in a sailing yacht’s keel, or variable,...

A black ball-shaped day signal used alone or in combinations to show a vessel’s status.

Depending on its number and arrangement with other...

A ridge of sand, gravel or other sediment that creates shallow water, often across or near a river or harbour entrance.

Depth over a bar can...

A line or tackle that changes a sheet’s lead position to adjust sail shape or sheeting angle.

A barber hauler may pull a headsail sheet...

The condition of a sailing vessel when all sails are lowered or stowed.

Even without sails set, wind acting on the hull, mast and rigging can...

An RYA course-completion certificate covering basic emergency survival techniques and safety equipment for people going to sea.

The one-day...