Overall Period 



JULY 1972 -DECEMBER 1978 



Summer 



APRIL TO SEPTEMBER 



Winter 



OCTOBER TO MARCH 



WAVE DIRECTION 



( Relative to Sliore Parallel ) 



DDE 



ANGLE (deq.) 



1 



6-= 55 



2 



55 S e < 70 



3 



70^0 -=80 



4 



80^0 <85 



5 



85 se -=90 



6 



=90 



CODE 



ANGLE (deg.) 



7 



9O<0 S 95 



8 



95 -=0 SIOO 



9 



100 -=0 S 110 



10 



110 -:0 SI25 



II 



125 <:0 ' 



WAVE HEIGHT (fl) 



0-2 2-4 



PERCENT 



Figure 17. Distribution of breaking wave directions at Sea Crest, North 

 Carolina. 



3. Currents. 



Visual observations of longshore currents have been made at Sea Crest (see 

 Fig. 1) since 1972 by timing the movement of floating foam in the surf zone. 

 A sample year of data (1973) is plotted in Figure 18. Although reversals are 

 common, the mean current from July 1972 to December 1978 was to the north. 

 This is in contrast to the predicted direction of longshore transport, based 

 on the visual wave data, which was predominantly to the south (see Sec. 

 IV, 5). Other currents which affect the area are rip currents, low salinity 

 water masses, and Gulf Stream eddies. 



Rip currents are frequently found at varying locations including under the 

 pier. The low-salinity water masses, believed to originate in the Chesapeake 

 Bay, are huge slugs of lower salinity water which move southward along the 

 shore at an estimated velocity of about 0.23 meter (0.75 foot) per second. 

 The edge is clearly discernible by both water color and turbulence. Two views 

 of the phenomena are shown in Figure 19. Warm, clear water masses presumaoly 

 resulting from Gulf Stream eddies have also been observed. These masses 

 sometimes have a foam-line edge and can contain tropical fish. 



41 



