wave direction is almost shore-normal). However, storm waves approach twice 

 as frequently from north of the pier. 



12. The annual mean wave height (measured at the seaward end of the FRF 

 pier) is 0.9 m, with a standard deviation of 0.6 m. Wave heights in excess of 

 2 m can be expected to occur 7 percent of the time, or 600 hr per year. 



13. Wave periods generally vary between 6 and 12 sec with an annual 

 mean peak spectral period of 8.8 sec and a standard deviation of 2.8 sec. 

 Wave periods tend to be longest during the fall and shortest during the 

 summer. 



Nearshore Currents 



14. Surface current speed and direction at the FRF are influenced by 

 winds, waves, and, indirectly, by the bottom topography. The extent of the 

 respective influence varies daily. However, winds tend to dominate the cur- 

 rents at the seaward end of the pier, while waves dominate within the surf 

 zone. The effect of the bottom topography is such that, under certain condi- 

 tions (e.g., near shore-normal wave angles), rip currents develop which inter- 

 rupt the general flow of the alongshore current. A trough located under the 

 seaward half of the pier is a preferred location for such currents. Currents 

 tend to be southward during fall and winter and northward during spring and 

 summer. 



Tides and Water Levels 



15. Ocean tides at the FRF are semidiurnal, with a mean range of 1.0m. 

 The highest water levels generally are associated with strong and persistent 

 onshore winds and high waves. Storm surges have resulted in a maximum water 

 level of 1.5m above the NGVD. Water levels in Currituck Sound are wind- 

 dominated rather than tidal, being low when winds are northerly and high when 

 winds are southerly. 



Bathymetry 



16. Nearshore bathymetry at the FRF is characterized by regular shore- 

 parallel contours, a moderate slope, and a barred surf zone (usually an outer 



15 



