similarity values and approaches a constant value for larger surf similarity 

 parameter values, whereas plunge distance on plane slopes shows a gradual 

 decrease with increasing surf similarity parameter. This could also be an 

 effect of the return flow, since return flow was observed to be stronger at 

 larger £ -values . 



147. Figure 47 shows no apparent trend for plunge distance normalized 

 by deepwater wave height plotted as a function of £ , which means that 

 plunge distance is insensitive to deepwater wave height. A representative 

 value visually determined from Figure 47 is Xp = 3 H . 



6.0 



5.0 



4.0 



Xp/Ho 



3.0 



0.0 0.5 



Figure 47 . Xp/H as a function of £ 



Splash Distance 



148. The procedure used to measure plunge distance was also applied to 

 measure splash distance. Splash distance normalized by H b as a function of 

 £ is shown in Figure 48. The data are extremely scattered and show no 

 trend. The splash distance is evidently not dependent on breaking wave 

 height. 



149. The ratio of plunge distance to splash distance ranged from 0.6 

 to 2.7, but average plunge distance was approximately equal to the splash 

 distance (Xp/X s = 0.95), which agrees with the result of Galvin (1968) for 



101 



