The part of a body of water deep enough to be used for navigation 

 through an area otherwise too shallow for navigation^ (3) A large 

 strait^ as the English Channel; (U) The deepest portion of a 

 streanij bay, or strait through which the main volume or current of 

 water flows. 



CHARACTERISTIC WAVE HEIGHT - See SIGNIFICANT WAVE HEIGHT. 



CHART DATUM - The plane or level to which soiindings on a chart are 



referred, usually taken to correspond to a low water stage of the 

 tide. See also DATUM PLANE. 



CHOP - The short-crested waves that may spring up quickly in a fairly 

 moderate breeze^ and break easily at the crest. Also WIND CHOP, 



CLAF0TI3 - (1) The French equivalent for a type of STANDING WAVE; (2) 

 In American usage it is usually associated with the standing wave 

 phenomenon caused by the reflection of a wave train from a break- 

 water j, bulkhead^ or steep beach, 



CLAY - See SOIL CLASSIFICATION. 



CLIFF ■= A high, steep face of rock; a precipice. See also SEA CLIFF. 



COAST - A strip of land of indefinite width (may be several miles) 



that extends from the seashore inland to the first major change in 

 terrain features ^ (See Figure l) 



COASTAL AREA - The land and sea area bordering the shore line, 

 (See Figure l) 



COASTAL PLAIN - The plain composed of horizontal or gently sloping 



strata of elastic materials fronting the coast and generally repre- 

 senting a strip of recently/- emerged sea bottom, 



COAST LINE - (1) Technically^ the line that forms the boundary between 

 the COAST and the SHORE; (2) Commonly, the line that forms the 

 boundary between the land and the water. 



COBBLE (COBBLESTOI^IE) - See SOIL CLASSIFICATION,, 



COI^IBER - (l) A deep water wave whose crest is pushed forward by a 

 strong vjind, much larger than a whitecap; (2) A long-period 

 spilling breaker, 



CONTINENTAL SHELF - The zone bordering a continent extending from the 



line of permanent immersion to the depth (usually about 100 fathoms) 

 where there is a marked or rather steep descent toward the great 

 depths « 



A-6 



