Gerassimov, Pershitz and Rakhmanin 



behaviour in the sea. The fishermen reported that when they observed 

 the behaviour of a vessel in windy weather (the yawing angle and the 

 drifting of the vessel), they were very surprised that the vessel turn- 

 ed not only beam to the wind direction but even more ; the stern of the 

 vessel had turned almost towards to the wind. 



We checked this behaviour in details and then set the problem 

 theoretically, I must say that the agreement is good between the 

 theoretical results and the full-scale data. The main purpose of this 

 paper was the representation of the theoretical considerations of the 

 phenomenon. 



I certainly agree with Dr. Dern that the presentation of the 

 results of the comparison between the theoretical and the experimen- 

 tal data would have been of interest. 



I regret that the authors were not able to check the theory 

 against model tests in order to determine how well their theory is 

 capable of predicting quantitatively the amplitude of the ship os- 

 cillations. 



■fr U.S. GOVERNMENT PRINTING OFFICE : 1975 O- 565-528 



1108 



