Reprint or republication of any of this material 

 shall give appropriate credit to the U.S. Army Coastal 

 Engineering Research Center. 



Limited free distribution within the United States 

 of single copies of this publication has been made by this 

 Center. Additional copies are available from: 



National Teahnioat Information Servioe 

 ATTN: Operations Division 

 5285 Port Royal Road 

 Springfield 3 Virginia 22151 



Contents of this report are not to be used for ad- 

 vertising, publication, or promotional purposes. Citation 

 of trade names does not constitute an official endorsement 

 or approval of the use of such commercial products. 



The findings in this report are not to be construed 

 as an official Department of the Army position unless so 

 designated by other authorized documents. 















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