transport of the magnitude employed in the model (Kraus and Dean 1987). 
60. The final output from this program is a sequential file that con- 
tains a 3-year time series of effective wave heights, periods, and directions 
at 6-hr intervals at the nominal 3-m depth for each of the 240 longshore grid 
lines. This file constitutes the principal wave input for the numerical model 
of shoreline change. 
Revision of nearshore bathym- 
etry and additional refraction runs 
61. At the request of CENAN, in May and June, 1985, staff of CERC's 
Field Research Facility (FRF) in Duck, North Carolina, made beach profile 
surveys in the project and neighboring beach area. Many of the control points 
used in the 1953 (CE 1954) and 1961 surveys were reestablished. In coordina- 
tion with CENAN and CERC personnel involved in the numerical modeling tasks, 
profile surveys were made at a density of approximately four lines per mile of 
shoreline in the stretch between the north end of Sea Bright and the south 
side of Shark River Inlet. In all, 68 lines were surveyed by the FRF in 1985. 
These lines extended from the control point well onshore, typically landward 
of the seawall, to a nominal depth of 9 m (30 ft). Elevations were measured 
relative to the National Geodetic Vertical Datum (NGVD). Sixty-five of the 68 
lines are located on the main refraction grid. The positions of the survey 
lines were converted from the original Easting and Northing coordinates to 
latitude and longitude and transferred to NOAA chart No. 12324. Depths from 
the surveys were read on to the grid and the bathymetry updated. Limited 
extrapolation and interpolation were done to update grid values immediately 
adjacent to the survey lines. 
62. The 1985 profile data became available after the processed time 
series and 56 refraction runs had already been generated. In order to deter- 
mine whether it would be necessary to repeat this considerable effort for the 
updated bathymetry, five refraction runs were made with unit wave height for 
the pre-1985 (original) and 1985 (updated) bathymetries. Selected pairs of 
wave period and direction were 8 sec, -67.5 deg; 10 sec, -52.5 deg; 8 sec, 
-7.5 deg; 5 sec, -22.5 deg; and 8 sec, -22.5 deg. Wave transformation coef- 
ficients and directions for each of these period-direction pairs were output 
at a nominal 3-m depth for the 240 longshore grid lines of the main grid. 
63. Example comparisons of calculated wave height and direction are 
given in Figure iia and Figure 11b, respectively. In these figures, the 
37 
