Get gear in condition for use; to separate the blocks of a tackle to lengthen the fall (ready for use again).

The difference between magnetic north and true north, measured as an angle. Magnetic variation is different in different geographic locations, so the nearest compass rose to each location on a chart must be used.

Ability of a filter to remove particle matter from an air stream. Measured by comparing concentrate of material upstream and downstream of the filter. Typical particulate sizes range from .3 micron to 50 micron.

Tank,one of which is situated at each side of the top part of the hold of a bulk carrier.

A party responsible for the payment as evidenced by the given instrument. Under letters of credit, the payer is the party on whom the draft is drawn, usually the drawee bank.

Relay to all others in order (a signal repeated from one ship to the next astern in column).

A unit used when measuring atmospheric pressure. 33.86 millibars.

A rail surrounding the poop deck.

Isolated rocky peak rising from a sheet of inland ice.

Ship's boat kept ready for immediate lowering while at sea. When used for life-saving, it was called an "accident boat" or lifeboat.

A slot into which the bolt rope or lugs in the luff of the sail are inserted to attach the sail.

An analytical method of assessing machine health by quantifying and examining ferrous wear particles suspended in the lubricant or hydraulic fluid.

Said of a vessel when caught between ice on both sides.

Is pressure as determined by most instruments and gauges.

Slang for anchor

A stopper used to prevent water from entering the hawse hole in heavy weather.

See Insurance, Particular Average.

A line with a weight on the end used to measure depth. The lead is dropped into the water and marks on the line are read to determine the current water depth. The lead usually has a cavity to return a sample of the bottom type mud, sand, etc.