SOLITARY WAVE. A wave consisting of a single elevation (above the original 

 water surface), whose height is not necessarily small compared to the 

 depth, and neither followed nor preceded by another elevation or 

 depression of the water surfaces. 



SORTING COEFFICIENT. A coefficient used in describing the distribution of 

 grain sizes in a sample of unconsolidated material. It is defined as S 

 = Q1/Q3 > where Qi is the diameter (in millimeters) which has 75 

 percent of the cumulative size-frequency (by weight) distribution smaller 

 than itself and 25 percent larger than itself, and Qo is that diameter 

 having 25 percent smaller and 75 percent larger than itself. 



SOUND (noun). (1) A wide waterway between the mainland and an island, or a 

 wide waterway connecting two sea areas. See also STRAIT. (2) A 

 relatively long arm of the sea or ocean forming a channel between an 

 island and a mainland or connecting two larger bodies, as a sea and the 

 ocean, or two parts of the same body; usually wider and more extensive 

 than a strait. 



SOUND (verb). To measure the depth of the water. 



SOUNDING. A measured depth of water. On hydrographic charts the soundings 

 are adjusted to a specific plane of reference (SOUNDING DATUM). 



SOUNDING DATUM. The plane to which soundings are referred. See also CHART 

 DATUM. 



SOUNDING LINE. A line, wire, or cord used in sounding, which is weighted at 

 one end with a plummet (sounding lead). Also LEAD LINE. 



SPILLING BREAKER. See BREAKER. 



SPIT. A small point of land or a narrow shoal projecting into a body of water 

 from the shore. (See Figure A-9.) 



SPIT, CUSPATE. See CUSPATE SPIT. 



SPRING TIDE. A tide that occurs at or near the time of new or full moon 

 (SYZYGY) and which rises highest and falls lowest from the mean sea level. 



STAND OF TIDE. A interval at high or low water when there is no sensible 

 change in the height of the tide. The water level is stationary at high 

 and low water for only an instant, but the change in level near these 

 times is so slow that it is not usually perceptible. See SLACK TIDE. 



STANDARD PROJECT HURRICANE. See HYPOTHETICAL HURRICANE. 



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