b. Specific . 



(1) The theory for plane slopes has been verified near the break- 

 ing limit. Further research at the breaking limit is needed, including wave 

 setdown investigations. 



(2) Limited evidence available suggests the theory is applicable 

 to two-dimensional nonbreaking wave transformation studies as presently con- 

 ducted with physical hydraulic models. 



(3) No wave breaking nor surf zone simulation results have been 

 published in the open literature. Such efforts have been recommended and 

 are currently being pursued by European researchers in coastal hydrodynamics. 



(4) Large high-speed computers are required for accurate simula- 

 tions. 



4. Data Base and Measurement . 



a. Data . 



(1) The overall data base to verify the theories is inadequate. 

 However, new laboratory experiments (Visser, 1980; Gourlay, 1978; Mizuguchi, 

 Oshima, and Horikawa, 1978) and field data (NSTS) are becoming available for 

 this purpose. 



(2) Results of the recent extensive NSTS field experiments need 

 further detailed study. The results are readily available for this purpose. 



(3) Additional controlled laboratory tests are needed to study 

 and verify aspects of both theories. A spiral wave maker can be readily 

 designed for this purpose. Tests with relatively flat beach slopes and bar- 

 trough profiles are critically needed to verify new surf zone energy dissi- 

 pation models. 



(4) New, extensive field investigations should be delayed until 

 analyses of the NSTS results are completed. 



(5) Field investigations of coastal hydrodynamics have yet to be 

 made on Gulf of Mexico beaches. Experiments on this relatively flat low- 

 energy coast are needed. 



(6) No data on the vertical current profiles over the water column 

 exist except for some rip current profiles. Also, long-term current time 

 histories are needed for statistical purposes at selected locations. 



(7) Further extensive use of the slope array device (Seymour, et 



al.) for direct measurement of S and a is recommended. 



xy 



b. Measurement . 



(1) The use of extensive arrays of fixed current meters in the 

 surf zone is the best way to obtain sufficient and useful field data for 

 verification of theory. 



(2) Current meters with flat gains beyond 2 hertz are needed to 

 obtain additional turbulence information in the surf zone. 



(3) The STEREO-BACS system could be significantly improved to 

 overcome problems with camera drift and surfboarding drogues but will be 

 limited to observations of nonstorm events. 



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