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

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

see Turnbuckle

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

The basic unit of measurement for lumber. One board foot is equal to a oneinch board, 12 inches wide and one foot long. Thus, a board ten feet long, 12 inches wide, and one inch thick contains ten board feet.

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.

A ball shaped buoy marking a navigational hazard.

See "Overland Common Points."

The magnetic compass used by the navigator as a standard.

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

Port of initial Customs entry of a vessel to any country. Also known as First Port of Call.

A vertical post extending above the deck for securing mooring lines

Specially designed for the transport of chemicals.

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

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.

The stationary seating surface, the inlet of a valve.

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

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

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

The operation of secretly bringing goods into a country to avoid paying duty on the goods. Also applies to illicit goods.