The process of plotting a theoretical position or future position based on advancing from a known position using speed, time, and course, without aid of objects on land, of sights, etc. Term comes from deduced reckoning, abbreviated first to "ded reckonin ...

A track or groove in the back of the mast to which the sail is attached by means of lugs or the bolt rope.

An opening such as a hole or vent. An opening through which air can pass, or a restricted opening placed in a pipe line to provide a means of controlling or measuring flow.

Is a technique for predicting whether water will tend to dissolve or precipitate calcium carbonate. If the water precipitates calcium carbonate, scale forming may result. If the water dissolves calcium carbonate, it has a corrosive tendency.

Little or no wind and flat seas

A suitable beach, being steep and sandy, where ships could be careened for cleaning or repair.

(Delivered Ex Quay, [Duty Paid]) (...Named Port of Destination):A Term of Sale which means the DDU term has been fulfilled when the goods have been available to the buyer on the quay (wharf) at the named port of destination, cleared for importation. The s ...

Gross tonnage is the basis on which manning rules and safety regulations are applied, and registration fees are reckoned. Port fees are also often reckoned on the basis of GT and NT. GT and NT are defined according to formulas which take account, among ot ...

A compartment having a watertight bulkhead at each end.

The small triangular space found at the intersection of lines of position on a chart when a ship's position is determined by taking three bearings.

Warehouse Withdrawal for Transportation Immediate Exportation.Allows merchandise that has been withdrawn from a bonded warehouse at one U.S. port to be exported from the same port exported without paying duty.

see Gybe

A small rail on tables and counters used to keep objects from sliding off when the vessel rolls and pitches.

Member of a crew who works all day but does not keep the normal watches.

A distinctive fixed reference point that can be used for navigation.

See Intracoastal Waterway.

A platform with or without sides, on which a number of packages or pieces may be loaded to facilitate handling by a lift truck.

A small wooden, metal or plastic insertion at the head of a mainsail.

Indirect heat exchanger designed to transfer heat from combustion gas to the air stream added to the combustion zone.

The average level of the oceans, used when finding water depths or land elevations.