The information on the performance of floating breakwaters, i.e., 

 their wave attenuating characteristics, mooring line forces, and motions, 

 is contained primarily in reports of laboratory scale. model tests with 

 monochromatic incident waves; the few exceptions are the early analytical 

 work by Carr (1951) and the occasional piece of information from a full- 

 scale test like that performed by Harris (1974) . There is a need for a 

 fundamental analytical procedure to predict the performance characteris- 

 tics of floating breakwaters with arbitrary cross section when exposed 

 to a given incident wave. This procedure could be used to systematically 

 compare performance information available in the literature, to examine 

 new design proposals, and either eliminate or reduce and systematize 

 auxiliary experimental studies. 



The development of the predictive procedure was the primary thrust 

 of the project with the concommitant field assessment of a full-scale 

 floating breakwater in operation at Friday Harbor, Washington (Fig. 1). 

 The analytical model developed from the two-dimensional, linearized so- 

 lutions of the hydrodynamical equations formulated in terms of a boun- 

 dary value problem for the velocity potential. The model was refined 

 progressively by comparisons with results already reported in the li- 

 terature, by auxiliary laboratory tests, and by the results from the Fri- 

 day Harbor field program, where measurements of incident and transmitted 

 waves, mooring line forces, and acceleration in sway, heave, and roll 

 were measured over a 6-month period. 



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