-29- DISCUSSION The extent of contamination of the water immediately following the Wahoo detonation was determined by means of gamma survey meters. This initial survey showed that at W + 1-1/2 one and one-half hours after Wahoo) the area of contamination extended one and one-half miles southeast of the target,and at W + 2-1/2, it west of target zero. extended about four miles The radioactivity of water samples taken at W + 5, about two miles southwest of target zero, was found mostly above the thermocline, although some radioactivity was found in the deeper samples. At W +27, survey meter measurements taken four miles west of target zero were not significantly greater than the pre-Wahoo levels. However, gross beta activity determinations of water from the same area contained high levels of radioactivity in the uppermost 50 meters and lesser amounts in the deeper water. taken at target zero, the was in water samples greatest amount of radioactivity was in the samples taken below the thermocline. water At W+48, moving horizontally These data show that the deeper at aslower rate than the water above the thermocline. The radioactivity measurements of the plankton showed that in three days the contamination had extended at least 50 miles to the west of target zero. Samples taken 20 miles to the south, about 10 hours « Ce 4S ant% ca) av ,