4. The literature on detached breakwaters yields little guidance for 

 determining the optimum configurations of these structures for shore protec- 

 tion and illustrates that their shoreline response is a complex phenomenon 

 which often cannot be predicted with great accuracy. The material presented 

 herein is based on a review of detached breakwaters built for shore stabili- 

 zation, with special emphasis on ten United States breakwater projects. The 

 reader is referred to Toyoshima (1972) and Lesnick (1979) for additional back- 

 ground material. Guidance for developing a breakwater cross section is avail- 

 able in the Shore Protection Manual (SPM 1984) . 



5. The design concepts presented are those required for developing a 

 breakwater plan and configuration. This guidance is intended to help the 

 coastal engineer or scientist predict sediment response to a detached break- 

 water. The design and application of the detached breakwater concept at any 

 particular site must be based on an evaluation of the local wave climate and 

 littoral transport regime, plus a review of the lessons learned from pre- 

 viously constructed projects. The site specific nature of detached breakwater 

 design and the habitual lack of coastal processes data for any particular site 

 introduces a level of complexity into detached breakwater design which can be 

 dealt with in this report in a qualitative sense only. Each project possesses 

 its own specific problems which cannot be anticipated in any general guidance. 

 Therefore, this report not only stresses design, philosophy, and theory, but 

 also the prototype experiences which are currently available to assist in 

 developing a detached breakwater plan. Although there are a limited number of 

 numerical and physical modeling procedures which may be used, the eventual 

 design must rely heavily on engineering judgment and experience on the local 

 coast. 



