GROIN (British, GROYNE) - A shore protection structure built (usually- 

 perpendicular to the shoreline) to trap littoral drift or retard 

 erosion of the shore. 



GROIN SYSTEM - A series of groins acting together to protect a section 

 of beach. Commonly called a groin field. 



GULF - A large embayment in a coast; the entrance is generally wider 

 than the length. 



HEADLAND (HEAD) - A high steep-faced promontory extending into the sea. 



HIGH WATER LINE - In strictness, the intersection of the plane of mean 

 high water with the shore. The shoreline delineated on the nautical 

 charts of the U.S. Coast and Geodetic Survey is an approximation of 

 the high water line. For specific occurrences, the highest eleva- 

 tion on the shore reached during a storm or rising tide, including 

 meteorological effects. 



IMPERMEABLE GROIN - A groin through which sand cannot pass. 



INLET - (1) A short, narrow waterway connecting a bay, lagoon, or similar 

 body of water with a large parent body of water. (2) An arm of the 

 sea (or other body of water), that is long compared to its width, 

 and may extend a considerable distance inland. 



ISTHMUS - A narrow strip of land, bordered on both sides by water, that 

 connects two larger bodies of land. 



JETTY - (1) (U.S. usage) On open seacoasts, a structure extending into 

 a body of water, and designed to prevent shoaling of a channel by 

 littoral materials, and to direct and confine the stream or tidal 

 flow. Jetties are built at the mouth of a river or tidal inlet to 

 help deepen and stabilize a channel. (2) (British usage) Jetty is 

 synonymous with "wharf" or "pier." 



LAGOON - A shallow body of water, as a pond or lake, usually connected 

 to the sea. 



LEADLINE - A line, wire, or cord used in sounding. It is weighted at one 

 end with a plummet (sounding lead) . 



LEVEE - A dike or embankment to protect land from inundation. 



LITTORAL - Of or pertaining to a shore, especially of the sea. 



LITTORAL DRIFT - The sedimentary material moved in the littoral zone 

 under the influence of waves and currents. 



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