Sand 



Rock fragments less than 0.75in (1.9crr) diameter. 



Scouring effect 



Removal of underwater material by waves and currents, especially at base 

 or toe of a structure. 



Seawa I I 



Structure separating land and water areas, primarily designed to protect 

 land from wave action; see 



Sedimentation 



Process of deposition of material, usually soil or organic detritus, in 

 the bottom of a liquid. 



Sessile 



Attached to substrate and not free to move about. 



Shingle 



Any beach material coarser than ordinary gravel, especially with flat or 

 roundish pebbles. 



Shoreline, eroding 



Shoreline which, by wave action, longshore current, or frequent storm 

 activity is losing material. 



Sill, sandbag 



A small breakwater used for shore protection which is constructed from 

 sand filled nylon tubes. Sandbag sills are usually placed parallel to 

 the shoreline and just below the intertidal zone. 



Silt 



Loose sedimentary materials with rock particles less than 0.05 mm 

 diameter. 



Slip 



Berthing space between two piers. 



Spandrel (bridge) 



A bridge with a series of arches supporting the roadway. 



Spawning 



Production and deposition of eggs, with reference to aquatic animals. 



Spit 



Small point of land or narrow shoal projecting into body of water from 

 shore. 



Spring tide 



Occurs at or near time of new or full moon and rises highest and falls 

 lowest from mean sea level. 



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