The ratio of the actual water-vapor partial pressure to its saturation pressure at the same temperature. (considered only with atmospheric air).

The riding lights required to be carried by vessels at anchor.

(1) A line by which the end of a spar is hoisted or lowered. (2) A line that holds up the boom when it is not being used. (3) A line from the upper mast which controls the height of the spinnaker pole.

A published rate that is never assessed because no freight moves under it.

A vessel whose bow and stern have drooped. The opposite of sagged.

Said of a vessel when the depth of water can be measured by the lead (within the 100 fathom curve).

An automatic or manual device designed to control pressure, flow or temperature.

Machines in which the compressing element is a piston having a reciprocating motion in a cylinder.

Shipped under rate that includes cost from end of ship's tackle at load port to end of ship's tackle at discharge port.

The outer layer on a coalescing filter that prevents separated liquids from re-entering the air stream. Also known as anti re-entrainment barrier.

The alternating motion of a boat, leaning alternately to port and starboard; the motion of a boat about its fore-and-aft axis.

A line used for capsizing the sea anchor and hauling it in.

(1) The edge where the deck joins the hull; top edge of bulwarks. (2) The railing around the deck.

Sailing with the motor on and in gear

Amount of unused space in a ship or a hold by virtue of the irregular shape of the cargo.

A mechanical barometer used to measure air pressure for warnings of changing weather.

Said of a man who goes to sea as a rating compared with officers, and lives forward. Forward of a mast.

Vessel moves to a new area for a new season.

Where the water and sky or ground and sky appear to intersect.

Carries supplies to drilling units or installations during field de-velopment or production.