the apparent crests are much longer. No individual crest can be 
followed very far by the eye before it becomes lost in an area of 
poor definition and low amplitudes. 
A second interesting feature is the local chop which is super- 
imposed on the longer apparent crests. At the far right, the crests 
are at about an eighty-five degree angle to the coast. Even near 
the coast, these short crested waves are only slightly affected by 
the bottom, and they have only turned a few degrees more parallel 
to the coast. The assumption of linearity, of course, assumes that 
neither system has an effect on the other which is not true for the 
higher order effects. 
A third interesting feature is found by a careful study of 
the zone between the coast and a line about one-eighth of the dis- 
tance to the outside edge of the photo and of the triangular zone 
at the base of the Oracoke photo. The crests in these zones do not 
have the same profile as the crests outside of the zones. The 
crests are higher and more peaked and the troughs are longer and 
shallower. Outside of the zones discussed above, the crests and 
troughs are equal in importance, and a graph (as a function of, 
Say, distance along a dominant orthogonal) of the wave height would 
look very much like a wave record except that the apparent crests 
would be shorter near the coast. The outside edge of this zone and 
some curve probably off the picture define the transition zone 
studied in this chapter. Note that the local chop keeps on doing what 
it had been doing before even after the longer crests have been 
modified in profile (see figure 37). 
(le) 
