EMBANKMENT - An artificial bank, mound, dike or the like, built to hold 

 back water, carry a roadway, etc. 



EMBAYED - Formed into a bay or bays, as an embayed shore, 



EMBAYMENT - An indentation in a shore line forming an open bay. 



ENERGY COEFFICIENT - The ratio of the energy in a wave per unit crest 

 length transmitted forward with the wave at a point in shallow 

 water to the energy in a wave per unit crest length transmitted 

 forward with the wave in deep water. On refraction diagrams this 

 is equal to the ratio of the distance between a pair of orthogo- 

 nals at a selected point to the distance between the same pair of 

 orthogonals in deep water. Also the square of the REFRACTION 

 COEFFICIENT. 



ENTRANCE - The avenue of access or opening to a navigable channel. 



EROSION - The wearing away of land by the action of natural forces. 



(See also SCOUR). On a BEACH, by carrying away of beach material 

 by wave action, tidal currents, or littoral currents or by the 

 action of the wind (see DEFLATION). 



ESCARPMENT - A more or less continuous line of cliffs or steep slopes 

 facing in one general direction which are caused by erosion or 

 faulting. Also SCARP. (See Figure A-l) 



ESTUARY - (l) That portion of a stream influenced by the tide of the 

 body of water into which it flows j (2) A bay, as the mouth of a 

 river, where the tide meets the river current. 



FAIRWAY - The parts of a waterway kept open and unobstructed for 

 navigation. 



FATHCM - A unit of measurement used for soundings. It is equal to 

 6 feet (1.83 meters). 



FATHOMETER - The copyrighted trade name for a type of echo soiinder. 



FEEDER BEACH - An artificially widened beach serving to no-urish down- 

 drift beaches by natural littoral currents or forces. 



FEEDER CURRENT - The ciirrent which flows parallel to shore before 



converging and forming the neck of a rip current. See also RIP. 



FETCH - (1) In wave forecasting, the continuous area of water over 

 which the wind blows in essentially a constant direction. Some- 

 times used synonymously with FETCH LENGTH, Also GENERATING AREA| 

 (2) In wind set-up phenomena, for inclosed bodies of water, the 

 distance between the points of maximum and minimum water surface 

 elevations. This would usually coincide with the longest axis 

 in the general wind direction, 



A-12 



