angle fi 1 created under natural conditions is typically gentler than 10 deg. 

 The relationship for barred profiles was compared with the equation developed 

 in this study for plane slopes. The plane-slope equation gave smaller values 

 of breaker depth index than the barred profile equation for ^ x = 5 deg for 

 low wave steepness and all wave steepnesses for 10-deg seaward angles. The 

 plane -slope equation gave larger breaker depth values than the barred profile 

 equation for /3 X = 5 deg and 0.02 < tt^L,, < 0.09 . 



177. Breaker height index was a stabler parameter for conditions in- 

 volving a strong return flow. Breaker height as a function of deepwater wave 

 steepness gave the same trend for bars as data collected on plane slopes. An 

 equation for the experimental data was expressed in the same form as the 

 analogous plane -slope equation. Breaker height decreased for ^ > 10 deg at 

 high wave steepnesses, but if wave steepness was low, breaker heights in- 

 creased as /#! increased. For high- steepness waves and steep bars, wave 

 shoaling was mostly caused by the plane slope because the bars were short and 

 had little effect on the waves. Return flow was not strong for these condi- 

 tions. If wave steepness was low and bars steep, a strong return flow was 

 present. A heuristic derivation was made to illustrate breaking wave height 

 increases as return velocity increases . 



178. Plunge distance normalized by breaking wave height was relatively 

 constant for larger values of the surf similarity parameter, but increased at 

 smaller values of the surf similarity parameter. Plunge distance was shorter 

 by a factor of approximately 2 if bars were present as compared with the 

 analogous plane-slope case, because breaker type differs with bars present. 

 Plunge distance normalized by deepwater wave height showed no dependence on 

 the surf similarity parameter, which indicates the distance traveled by the 

 plunging wave depends on the local (breaking) wave height. 



179. The average of plunge distance divided by splash distance was 

 approximately unity, which agrees with findings of Galvin (1969) for plane 

 slopes, but the plunge -to -splash distance ratio increased for smaller valued 

 surf similarity parameters. Plunge distance was also greater for smaller surf 

 similarity values. Splash distance normalized by deepwater and breaking wave 

 height was essentially constant if expressed as a function of surf similarity, 

 but the data were widely scattered. 



180. For barred profiles, the total distance traveled by the wave crest 

 from the break point was called the penetration distance. Penetration 



145 



