Step 3. — A deep water wave front (W W) is drawn in for 

 the direction to be studied. A suitable interval for orthog- 

 onals is stepped off and the directions of the deep water 

 orthogonals are drawn in. These are all straight lines, of 

 course. The direction selected was from the NW. Deep 

 water refers to depths greater than Z/o/2 as described in the 

 text, in this case 50 fathoms. 



Case 1. — Regular, simple hydrography, no angles in excess 

 of 80°. 



Step 4- — The diagram is started on any orthogonal. If 

 the K value is required for a partiular point on the beach, 

 orthogonals can be selected which will reach the point. 

 AZ, 



Where the 



Lai 



values are small, two contour intervals 



oan be crossed simultaneously. Thus, the first point select- 

 ed is Pi, where the orthogonal intersects the second con- 

 tour, a is measured to an estimated line PiP\' which is the 

 direction of level bottom at the point Pi. In this case it 

 is a line tangent to d2<^2'- 



Figure 1 5. 



24 



