It is to be noted that for a particular beach the scale showing values 

 of a in Diagram B could be replaced by a scale which shows the true 

 azimuth of the wave direction . For example, in the diagram for Las Pulgas 

 Beach (Figure 1) the true azimuth of the beach is 233 degrees; hence, this 

 azimuth is equivalent to an oc of zero degrees , Points of the compass 

 also may be indicated on the scale . 



Diagram C is plotted alongside Diagram B with a common ordinate 

 scale, H b /H . Thus, for a particular wave direction oc and value of Hq/T 2 

 obtained from Diagram A, H-^/Hq is obtained from diagram B. For this value 

 of Ht,/H , the breaker height Hb is obtained from -Diagram C for the forecast 

 value of H o 



Breaker Depth 



To obtain the depth of breaking for breakers of a certain height and 

 period, the data is Plate III of H,0. No. 234. has been replotted to give 

 Diagram Do For a particular period the depth of breaking, d^, is obtained 

 from Plate III for various breaker heights, H^. These plotting data are 

 given in Table lie 



TABLE II 



VALUES AT DEPTH OF BREAKING 



(Obtained from Plate III, H.O. No. 234) 



T (sec, 

 Hb 



(ft.) 





























4 



5 





6 



7 



8 



9 



10 



12 



14 



16 



18 



1 



1,2 



1, 



.3 



1.5 



1.8 



1.8 



2„0 



2,0 



2,1 



2,4 



2,8 



3.0 



2 



2o5 



2, 



,6 



2,8 



3.0 



3.2 



3.3 



3.4 



3.6 



3.9 



4.4 



4.6 



3 



3.7 



3.8 



4.0 



4.2 



4.4 



4.6 



4.8 



5.2 



5.5 



6,0 



6.2 



4 



5.3 



5. 



,1 



5.1 



5.3 



5.5 



5.7 



6.0 



6.5 



7.0 



7.3 



7.7 



5 



7»0 



6.5 



6,3 



6.5 



6.6 



6.9 



7.3 



7.7 



8,2 



8,6 



9.0 



6 



8„7 



8, 



,0 



7,5 



7.5 



7.7 



8.0 



8,4 



9.1 



9.5 



10.0 



10.4 



7 



10 „9 



9, 



,5 



9d 



8.8 



8„8 



9.2 



9.5 



10.3 



10.8 



11„2 



11.6 



8 





11, 



,1 



10,4 



10.1 



10.1 



10.3 



10,6 



11.4 



12„2 



12.6 



13.0 



9 









11.8 



11.4 



11.3 



11.5 



11,8 



12,6 



13.5 



13.8 



14.2 



10 









13.5 



12,7 



12.5 



12,6 



12 ,9 



13.8 



14.8 



15.2 



15.6 



11 









15.2 



14.2 



13.7 



13.7 



14.0 



15.0 



16,2 



16.5 



16.9 



12 









17.2 



15.7 



15.1 



14.9 



15.1 



16.2 



17.3 



17.8 



18.2 



13 









19.1 



17.4 



16.6 



16.2 



16.3 



17.4 



18,5 



19.0 



19.5 



14 













18,0 



17.5 



17.5 



18,5 



19.5 



20,1 



?20„6 



15 

















18.7 



19.7 

 20.5 



20,5 



21.1 



21 .7 

 23.3 



16 



















20.8 



21,4 



22,35 



22 „9 



17 





















21 .4 



23.2 



24.0 



18 





















23.5 



25.3 



25.2 



19 

























26.5 



20 

























27.9 



27 



