region. Currents are strong on the Inside of the north jetty because waves 

 advance and break along the jetty. These currents have a westerly direction 

 and advance into the inlet. Because of diffraction, currents are very weak 

 behind the north jetty. 



100. Figure 15 corresponds to a wave of period 7.8 sec coming from 

 azimuth 80 deg in 63-ft depth of water msl (Case B) . In this case, since the 

 waves are approximately normal to the shoreline and the offshore contours, 

 there is not much refraction of the waves offshore or even near the straight 

 line portion of the shoreline. The waves converge on the south shoal, because 

 of refraction, resulting in higher wave heights on the shoal. There is a 

 similar convergence on the north shoal and a small divergence of wave energy 

 near Cumberland Island. The incident wave direction is such that there is 

 very little sheltering due to the two jetties. As a result the waves propa- 

 gate straight and far into the inlet because the depth contours are approxi- 

 mately straight and parallel to the waves inside the jetties. The wave 

 heights are large between the jetties. 



101. Figure 16 displays the wave-induced currents for Case B. In this 

 case, because the incident waves are approximately normal to the shoreline, 

 there are no noticeable currents along the straight portions of the shoreline. 

 Because of wave convergence and breaking, the currents are strong over the 

 south shoal. A circulation pattern may be observed on the shoal. As the 

 waves propagate straight and unchanged between the jetties without breaking or 

 decaying, there are no noticeable wave-induced currents in this region. Cur- 

 rents may be observed on the north shoal because of wave convergence, break- 

 ing, and decay there. These currents are smaller than those observed on the 

 south shoal. 



102. Figure 17 corresponds to a wave of period 6.9 sec and azimuth 

 60 deg in 63-ft depth of water msl (Case C) . The waves refract on the off- 

 shore shoal. They refract and converge strongly on the north and south 

 shoals, resulting in higher wave heights on both shoals. Since the waves are 

 aligned approximately parallel to the two jetties, there is very little 

 sheltering due to the jetties so that the waves propagate deep into the area 

 between the jetties. They break and decay near the straight portions of the 

 shoreline. 



103. Figure 18 represents the wave-induced currents for Case C. Near 

 the straight reaches of the shoreline the currents are parallel to the shore 



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