118 NAUTICAL CHART MANUAL 



TERMINOLOGY 



The following definitions, primarily for physiographic terms, are given to clarify and 

 standardize usage on C&GS nautical charts. These definitions are limited to connotations 

 applicable to nautical and bathymetric charting. 



Archipelagic apron A gentle slope with a generally smooth surface on the sea floor 



found around groups of islands or seamounts. 



Archipelago A sea or broad expanse of water studded with many islands or 



a groups of islands; also, such a group of islands. 



Arroyo The course of an intermittent stream steep-cut in loose earth; 



a coulee ; a steep-waUed trenchlike valley. (Local in South- 

 west.) 



Atoll A ring-shaped reef with or without islands encircling a lagoon. 



Bald A high rounded knob or mountain top, bare of forest. (Local 



in Southern States.) 



Bank The edge of a cut or fill; the margin of a watercourse; an 



elevation of the sea floor located on a Continental Shelf or an 

 Island Shelf and over which the depth of water is relatively 

 shaUow but sufficient for safe surface navigation. (Reefs or 

 shoals, dangerous to surface navigation, may rise above the 

 general depths of a bank. ) 



Bar A ridge or mound of sand, gravel, or other unconsolidated 



material below high-water level, especially at the mouth of a 

 river or estuary, or lying a short distance from and usually 

 parallel to the beach. 



Barrier beach A beach separated from the mainland by a lagoon or marsh. 



Barrier island A detached portion of a barrier beach between two inlets. 



Basin A large depression of a general circular, elliptical, or oval 



shape ; the drainage or catchment area of a stream or lake ; a 

 depression of the sea floor more or less equidimensional in 

 form (when the length is much greater than the width, the 

 feature is a trough). 



Bathymetry Submarine topography (q.v.), esp. as applied to oceanographic 



studies. 



Bay A recess in the shore, or an inlet of a sea or lake between two 



capes or headlands, not as large as a gulf but larger than a 

 cove. 



Bayou A widely (and loosely) used term along the Gulf Coast, most 



often applied to a creek or small river with tortuous course 

 and sluggish current; a lake, often in an abandoned stream 

 channel; a connecting channel. 



Beach The gently sloping shore which is washed by waves or tides, 



especially the parts covered by sand or pebbles. 



Bed The floor or bottom on which any body of water rests. 



Bench A strip or relatively level earth or rock, raised and narrow. 



A small terrace, or comparatively level platform, breaking 

 the continuity of a declivity. 



Bery A hill or mountain. Local in Hudson River Valley. Also, an 



iceberg. 



