A map used for navigation at sea, with water depths and coast line features marked. Often referred to as Admiralty Charts.
George Stephen Ritchie has written: 'The Admiralty chart' -- subject(s): Great Britain, Great Britain. Hydrographic Office, Hydrographic surveying
Togograph chart
A map or chart showing depths of water, the nature of the bottom, contours of the bottom and coastline, and the tides and currents in sea.
shoreline contour guide
Norwegian Hydrographic Service was created in 1932.
Norwegian Hydrographic Service ended in 1986.
for ease of explanation, a map is generally land based and a chart refers to hydrographic or marine locations. The original meaning of chart was a 'map used for navigators' came into being in the mid 1500's. From the Latin 'Charta'
United Kingdom Hydrographic Office was created in 1795.
Pakistan Navy Hydrographic Department was created in 1959.
One thing that hydrographic surveys are used to find is the depth of the water. Hydrographic surveys are also used in order to identify objects in the water.
A sheet of paper, pasteboard, or the like, on which information is exhibited, esp. when the information is arranged in tabular form; as, an historical chart., A map; esp., a hydrographic or marine map; a map on which is projected a portion of water and the land which it surrounds, or by which it is surrounded, intended especially for the use of seamen; as, the United States Coast Survey charts; the English Admiralty charts., A written deed; a charter., To lay down in a chart; to map; to delineate; as, to chart a coast.
Correction: What is hydrographic datum? not "hydrography"