A barrier, together with appurtenant structures, constructed for the purposes of storage, control and diversion of water. A dam may be constructed across a natural watercourse or on the periphery of a reservoir.

An open body of water entirely surrounded by land either naturally formed or man-made

Line containing point of the same depth with survey data.

Depth obtained through sounding by means of any sounding equipment. 

An area within which naval, military or aerial exercises are carried out also called an exercise area.

A specified area designated by an appropriate authority within which navigation is restricted in accordance with certain specified conditions.

A floating object moored to the seabed in a charted place as a navigation aid or for other specific purpose.

A tower or structure containing a beacon light to warn or guide ships.

A prominent specially constructed object forming a conspicuous mark as fixed aid to navigation.

A long, narrow structure extending into the water to afford a berthing place for vessels, to serve as a promenade, etc.