In 1942 work on sea and swell forecasting had 
been started independently in Great Britain, and 
some of the ideas developed there were of value 
to the authors, although the numerical relation- 
ships differed. Subsequently Commander C. T. 
Suthons, British Admiraity, developed relation- 
ships on an empirical basis which, with a few 
important exceptions, are similar to the ones 
presented here. 
This paper does not deal with the forecasting 
technique, but a practical manual in forecasting 
was prepared in September 1943 on -the basis of 
the 1943 report and published by the Hydro- 
graphic Office (19442) in March 1944. The 
relation between swell and surf is not covered in 
the present paper nor in the forecasting manual, 
but studies of the transformation of waves in 
shallow water at the Woods Hole Oceanographic 
Institution; the Beach Erosion Board; the Depart- 
ment of Mechanical Engineering, University of 
California, Berkeley; and the Scripps Institution 
led to the joint preparation of . second manual 
on the forecasting of breakers and surf, published 
- wholehearted support. 
by the Hydrographic Office (1944b) m November 
1944. 
The authors are indebted to the Army Air 
Forces for initial encouragement and to the 
United States Navy, which gave the program its 
They are also indebted 
to the Oceanographic Research Group, Admiralty 
Research Laboratory, Teddington, England, for 
having made available unpublished records of 
swell at Pendeen near Land’s end. In the 
preparation of this manuscript the authors have 
been greatly aided by Lt. R. S. Arthur, USNR; 
Capt. J. C. Burke, AUS, AC; Lt. Gg) J. F. Munch, 
USNR; Sgt. R. E. Jentoft, AUS, AC; and Capt. 
M.A. Traylor, USMCR; all of whom were assigned 
to the project at the Scripps Institution. 
The authors are also indebted to about 200 
weather officers of the Army Air Forces and of 
the Navy, who attended the courses in sea and 
surf forecasting at the Scripps Institution and 
whose questions and interest have contributed 
much to improve the understanding of the prob- 
lems. 
