(e) Wave Forecasting 



Methods of forecasting for shallow water generation (as the 

 continental shelf of the Gulf of Mexico) have been developed to include 

 the effect of friction, refraction and shoaling, and a report will be 

 issued in the next year. An analysis and comparison of the Bretschneider 

 revised Sverdrup-Munk method with the spectrum method developed by 

 Neumann and Pierson is being made. 



(f ) Maximum Water Stage Level Recorder 



A maximum water stage level recorder similar to that used by 

 the Geological Survey for determining maximum river flood stages was 

 tested to determine the effect of superficial wave action in displacing 

 the reading. A modification to the gage, essentially choking down the 

 inlet area to the gage, resulted in excess rises inside the gage (errors) 

 being less than one tenth of the wave height, never amounting to greater 

 than 0.3 foot. Such a gage could possibly be used economically around 

 estuaries to obtain maximum hurricane tide levels. 



(g) Wave Run-up 



Testing of eight smooth slopes ranging in steepness from 1 on 

 30 to a vertical wall has been completed and a report by Saville "Wave 

 Run-up on Structures" published by the American Society of Civil Engineers. 

 Most of these slopes have been tested for the effect of roughness on 

 wave run-up by roughening the slopes with five sand sizes ranging from 

 0.2 mm. to 6.50 mm. in median diameter. About half of the slopes have 

 been tested for the effect of permeability on wave run-up for the same 

 sands used in the roughness test. The data show that slope roughness and 

 permeability reduce wave run-up considerably below that observed for smooth 

 slopes. 



(h) Study of Sand By-Passing Operation at Port Hueneme 



As a continuation of the observational program, a survey of the 

 area was made in June 195 6. The data taken before, during, and after 

 the Port Hueneme dredging project to June 1955 has been analysed and a 

 report has been prepared. The report indicates that if sand movement 

 continues at the rates indicated, the dredged area will be filled by 

 June 1957 and the erosion downbeach will again reach the Pt. Mugu area 

 by June 1959. Serious erosion is already occurring immediately south- 

 east of the east jetty. 



(i) Recorded Wave Characteristics 



Routine compilations were made of recorded wave characteristics 

 at: Cape Henry, Virginia; Huntington Beach, California; Daytona Beach, 

 Florida; Clearwater Beach, Florida; Palm Beach, Florida; Evanston, Illinois; 

 Bay Marchand, Louisiana. 



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