The work of Stokes showed that particles in an irrotational, pro- 

 gressive, gravity wave motion would undergo a slow drift. A de- 

 scription of this phenomenon now seems to be obtainable by a simple 

 extension of present gravity wave forecasting models. 



ACKNOWLEDGMENTS 



The authors wish to acknowledge the assistance of Miss Catherine 

 Vail in handling the data tapes and in aiding in the computations. 

 This research was sponsored by the Office of Naval Research under 

 Contract Nonr 285(57). 



TABLE I 



Frequency and direction bands for the spectral estimates 

 used in calculating the Stokes' drift 



Angular frequencies 

 (rad/sec) 

 From To Center 



0.226194-0.263893 0.244353 



0.263893-0.295309 0.279224 



0.295309-0.333008 0.314159 



0.333008-0.364424 0.349093 



0.364424-0.402123 0.383965 



0.402123-0.433539 0.418899 



0.433539-0.471238 0.453771 



0.471238-0.502654 0.488706 



0.502654-0.540353 0.523577 



0.540353-0.609468 0.575979 



0.609468-0.678583 0.645785 



0.678583-0.785397 0.733059 



0.785397-0.892211 0.837548 



0,892211-1.029751 0.959945 



1.029751- 00 1.030441 



406 



