FOREWORD 



The duration of favorable and unfavorable wave conditions is of 

 prime importance to shipping concerns for economic purposes, to coastal 

 installations for protective purposes, and to the Navy for military 

 expediency. When used simultaneously with other available information, 

 wave persistence data are especially beneficial to forecasting personnel 

 and shipmasters in ship routing and to design engineers in coastal 

 construction. 



This is one of a series of reports published by the U, S, Naval 

 Oceanographic Office in its continuous endeavor to improve the ship 

 routing program and its deep concern for the safety of ships at sea. 



i^y^w^ 



DENTS 1^ KNOLL 



Rear -idmiral, U. S. Navy 



Commander 



U. S. Naval Oceanographic Office 



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