PREFACE 
Two empirical models for the distribution of significant wave height are 
given in Section 4.332 of the Shore Protection Manual. A similar model is 
presented in this report. The model is based on a three-parameter Weibull 
distribution function. Parameters in the model are evaluated from a large 
sample of shallow-water gage data at Nags Head, North Carolina. The model, 
which more closely represents available data than either of the previous 
models, is particularly useful for statistical prediction of extreme signifi- 
cant wave heights in shallow water at Nags Head. The technique is applicable 
for other gage sites. This work was carried out under the waves and coastal 
flooding research program of the U.S. Army Coastal Engineering Research 
Center (CERC). 
This report was prepared by Edward F. Thompson, Hydraulic Engineer, under 
the supervision of Dr. C.L. Vincent, Chief, Coastal Oceanography Branch. The 
author gratefully acknowledges Dr. D.L. Harris, formerly CERC Senior Scien- 
tist, who provided valuable comments on this study, and J. Peworchik of CERC 
who processed the Nags Head data for the study. 
Comments on this publication are invited. 
Approved for publication in accordance with Public Law 1966, 79th Congress, 
approved 31 July 1945, as supplemented by Public Law 1972, 88th Congress, 
approved 7 November 1963. 
TED E. BISHOP 
Colonel, Corps of Engineers 
Commander and Director 
