The point (speed of sound) at which air flow through an orifice can not increase regardless of pressure drop.

To temporarily stop all movement of a line through a block by placing the hauling part across the sheave of the block. This jams the sheave and holds it tight, and a pull on the hauling part will release it.

A device that indicates pressure differential above or below atmospheric pressure.

A bollard with horizontal arms, forming the shape of a cross, as a means of belaying lines.

see Turnbuckle

The triangle formed by the masthead, the base of the mast at deck level, and the lower end of the headstay.

Light-weight foresail similar to a spinnaker but set without a pole.

A marine hardware store.

A single outlet or limited number of outlets in a building used to connect tools or equipment to the air system.

The magnetic compass used by the navigator as a standard.

A vertical post extending above the deck for securing mooring lines

The stationary seating surface, the inlet of a valve.

The place at which a shipment is received by a carrier from the shipper.

A metal fitting with an arm that uses a spring to close automatically when connected to another object.

An apparatus consisting of an outside shell and a sheave through which a rope may be passed (pulley).

A written contract between the owner of a vessel and the person desiring to employ the vessel (charterer); sets forth the terms of the arrangement such as duration of agreement, freight rate and ports involved in the trip.

Specially designed for the transport of chemicals.

On a square-rigged ship, a light weather sail set next above the royal in fair weather.

C The international temperature scale where water freezes at 0 (degrees) and boils at 100 (degrees). Also known as the centigrade scale.

Center point of all underwater area of the hull where the hull's lateral resistance can be said to be centered.