a circular donut-shaped buoy designed to support a person in the water. It is attached to the vessel with a (floating) line so that the person can be hauled back to the boat.

A depth measuring device.

A large foresail or jib that overlaps the mainsail. Also known as a genny. Can be expressed in percentages of overlap, e.g. 150 Genoa is 50% overlap of the mainsail.

To break loose from a mooring, anchor or docking.

The ring bolted to the upper end of the shank of an anchor and to which the bending shackle secures.

The bridge used for taking observations, or directing the handling of the ship.

An inspection cover or port in an air receiver tank.

A container fitted with a means of forced air ventilation.

Said of anchor when it is under ship's forefoot, and cable is nearly up and down.

The part of the upper deck which is abaft the mainmast, or in that general location of a ship without one. The quarterdeck was normally reserved for officers.

Any person or entity who, in a contract of carriage, undertakes to perform or to procure the performance of carriage by rail, road, sea, air, inland waterway or by a combination of such modes.

A lubricating oil made with synthetic base stocks.

The action of letting go the sheets of a sailing vessel, thus spilling the wind and reducing the forward motion of the boat.

Steel disc, that is dogged down over a porthole to secure against breakage of the glass and to prevent light from showing through.

A small crane that projects over the side of the boat to raise or lower objects (such as smaller boats) from or to the water.

The white froth on the crests of waves.

Combination minimum pressure valve and check valve.

Is the ratio of the polytropic compression energy transferred to the gas to the actual energy transferred to the gas.

Is a gas that follows the perfect gas laws without deviation. There is no such thing, however it is the basis from which calculations are made and corrections applied.

Alternatively letting the sails draw, then spilling wind so as to keep a vessel more or less in one place until space is available, marking time.