given in Table 9; the values are summarized in Table 10. The average 
median at O hours was 0.20 millimeter. In the foreshore zone, the mean 
median increased to 0.22 millimeter at 50 hours and remained at 0.22 
millimeter at 80 hours. The range of values increased from a range of 
0.02 millimeter at 0 hours to 0.10 millimeter (including coarser values) 
at 50 hours and then decreased to a range of 0.08 millimeter at 80 hours. 
In the offshore zone, the mean median remained at 0.20 millimeter during 
the first 50 hours and then decreased to 0.19 millimeter at 80 hours. The 
range of values increased from a range of 0.02 millimeter at 0 hours to 
0.12 millimeter (including finer values) at 50 hours and then decreased 
to a range of 0.08 millimeter at 80 hours. 
In general, the foreshore became coarser and included more coarse 
samples, and the offshore maintained the same mean median but had more 
fine samples. 
4. Breaker Characteristics. 
A plot of breaker position (dashline) superimposed on a plot of con- 
tour movement along range 3 in experiment 72A-06 is shown in Figure 36. 
The wave broke mainly by surging or collapsing, and occasionally by 
spilling, near the base of the foreshore. 
A similar plot of breaker position along range 5 in experiment 72A-10 
is shown in Figure 37. The wave broke mainly by collapsing, and occasion- 
ally by plunging, near the base of the foreshore. 
5. Water Temperature. 
Figure 38 gives data on daily average water temperature versus both 
cumulative test time and dates for experiments 72A-06 and 72A-10. 
6. Wave-Generated Currents. 
a. Experiment 72A-06. Observations of wave-generated surface 
currents were collected during each run up to 85 hours and during runs 
between 125 and 135 hours. As pointed out in Section II,l,c (see Figs. 
1, 7, and 8), antinodes of the standing wave envelope occurred near 
Stations 5 and 18. During the first 70 hours a repeatable circulation 
pattern developed in the foreshore zone and between the first two 
antinodes of the standing wave envelope. The various pathlines followed 
by the bobs are indicated by the numbered lines in Figure 39. Table 11 
gives the maximum, minimum, and average velocities, path lengths, and 
number of velocity measurements for each of the pathlines in this experi- 
ment. Path number 0-1 in Figure 39 indicates the only path taken by bobs 
passing from the foreshore zone to the offshore zone, and path number F-8 
the only path taken from the offshore to the foreshore. The antinode near 
station 18 was a complete barrier during the first 70 hours; i.e., all 
bobs that moved seaward from station +5 returned, and no bobs moved sea- 
ward of station +16. 
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