PREFACE 



As waves move toward the shoreline they become increasingly nonlinear with 

 the elevation of the wave crests becoming relatively large and short in dura- 

 tion. This report is published to provide coastal engineers with techniques 

 for estimating crest elevation and duration. The techniques were developed 

 using laboratory data from a number of sources covering a wide range of con- 

 ditions for both monochromatic and irregular waves under nonbreaking and 

 breaking conditions. Predictions compare favorably with wave observations 

 made at the U.S. Army Coastal Engineering Research Center's (CERC) Field 

 Research Facility at Duck, North Carolina. The work was carried out under 

 CERC's Wave Estimation for Design work unit. Coastal Flooding and Storm Pro- 

 tection Program, Coastal Engineering Area of Civil Works Research and Develop- 

 ment. 



This report was prepared by William N. Seelig, Research Hydraulic Engineer, 

 John P. Ahrens, Oceanographer, and William G. Grosskopf, Hydraulic Engineer, 

 under the general supervision of Dr. R.M. Sorenson, Chief, Coastal Processes 

 and Structures Branch and Mr. R.P. Savage, Chief, Research Division. 



Technical Director of CERC was Dr. Robert W. Whalin, P.E. 



Approved for publication in accordance with Public Law 166, 79th Congress, 

 approved 31 July 1945, as supplemented by Public Law 172, 88th Congress, 

 approved 7 November 1963. 



TED E. BISHOP 



Colonel, Corps of Engineers 



Commander and Director 



