BULKHEAD - A structure separating land and water areas « primarily 

 designed to resist earth pressures » See also SEAWALL <, 



BUOY - A floatj especially a floating object moored to the bottom^ 

 to mark a channel, anchor , shoal rock, etco Some common t;/pess 

 A nun or nut buoy is conical in shape; « 



A can buoy is squat, and cylindrical or nearly cylindrical 

 above water and conical below water, 



A spar buojr is a vertical j, slender spar anchored at one end; 

 A bell buoy is one having a bell operated mechanically or by 

 the action of waves^ usually marking shoals or rocksj 

 A whistling buoy is similarly operated^ marking shoals or 

 channel entrances; 

 A dan buoy carries a pole with a flag or light on ito 



BUOYANCY - The resultant of upward forces j exerted by the water on a 

 submerged or floating body^ equal to the weight of the water dis- 

 placed by this body, 



CANAL - An artificial watercourse cut through a land area for use in 

 navigation, irrigation^ etc* 



CANYON - (1) (Oceanographical) A deep submarine depression of valley 

 form with relatively steep sides; (2) (Geographical) A deep gorge 

 or ravine with steep sides j often with a river flowing at the 

 bottom of it. 



CAPE - A relatively extensive land area jutting seaward from a conti- 

 nent or large island which prominently marks a change in, or 

 interrupts notably, the coastal trend; a prominent feature o 

 (See Figure A-6) 



CAPILLARY WAVE - A wave whose velocity of propagation is controlled 

 primarily by the surface tension of the liquid in which the wave 



is travellingo Water waves of length less than one inch are 

 considered to be capillary waves o 



CAUSEWAY - A raised road, across wet or marshy ground or across water. 



CAUSTIC - In refraction of waves, the name given to the curve to which 

 adjacent orthogonals of waves, refracted by a bottom whose contour 

 lines are curved, are tangents. The occurrence of a caustic al- 

 ways marks a region of crossed orthogonals and high wave conver- 

 gence » 



CAY - See KEY. 



CHANNEL - (l) A natural or artificial waterway of perceptible extent 

 which either periodically or continuously contains moving water, 

 or which forms a connecting link between two bodies of water; (2) 



A-5 



