maximum fetch was 300 km so that wind waves and swell from distant generating 

 areas (as would occur in an oceanic environment) were not present. Thus, 

 while this work is invaluable for studies of local wind wave generation 

 dynamics and for some measure of the climate in a bounded (lake) environment, 

 it does not satisfy the need for oceanic observations. 



34. In summary, it is intuitively, theoretically, and experimentally 

 known that detailed directional characteristics of waves incident to shallow, 

 nearshore waters are fundamentally important to coastal processes affecting 

 any engineering endeavor undertaken. Aside from some valuable but shadowy 

 hints of the bulk directional distribution statistics of wind wave energy, 

 there are insufficient direct observations of these distributions to guide an 

 engineer in project design. 



Measurement Program 



35. To help alleviate this dearth of knowledge, a program was begun in 

 September 1986 to collect and analyze high- resolution directional wave data at 

 CERC's Field Research Facility (FRF) located near the middle of Currituck 

 Spit, just north of the village of Duck, NC (Figure 1). The intent was to 

 create a long-term database, augmented by the ongoing climatological measure- 

 ments at the FRF, which would provide a detailed picture of the statistics and 

 dynamics of wave fields incident at that site. 



36. The FRF was chosen as the site for several reasons. It is rep- 

 resentative of many coastal sites characterized by (a) broad continental 

 shelf, (b) relatively mild bottom slope, and (c) reasonably uniform longshore 

 topography. These properties also make the site ideal for measurements with a 

 high-resolution spatial array gage. The mild sloping bottom substantially 

 dissipates wind waves so that attention can be focused on waves arriving (or 

 attacking) from seaward. The angular viewing window can thus be reduced from 

 the full 360-deg circle required in deep water or near a reflecting structure 

 to the 180-deg half -circle of incoming wave directions. Further, the FRF's 

 permanent staff and computing facilities can be used to monitor, maintain, and 

 error check the directional gage on a day-to-day basis to minimize data losses 

 from the myriad problems that can plague field data collection. 



37. The site does not represent all possible coastal sites, so the 

 detailed results are not expected to be universal. Results from this site are 



15 



