feet (457 meters) (Reference 16, Tab 0). Figure 89 shows the dimensions of the cloud based on the aerial tracking observations. At 0900 the Bairoko, vey helicopters. 10 nmi (19 km) off Eneu, launched radsafe sur- This survey covered the islands of the atoll and was conclusive enough to limit data-recovery operations to Eneu and Aerokoj on the first day. This survey indicated that recontamination was extensive throughout the atoll and lagoon both to the east and west. The radiation intensities on islands of the atoll are shown in Table 50. No significant secondary fallout was encountered at Bikini as a result of this detonation. Lagoon water was heavily contaminated with radioactive sediment. ings of 1 R/hr were obtained at a 100-foot (30.5-meter) cinity of ground zero on D+tl. 3 R/hr on shot day. Read- altitude in the vi- Floating objects revealed readings of 1 to Small boats and barges in Bikini-Eneu anchorage were contaminated to a moderate degree (1 to 6 R/hr). The initial radsafe re- ports indicated that the lagoon was too contaminated for reentry by the fleet. Following a conference, the decision was made for the Estes to re- turn to Enewetak while other ships remained at sea in the Bikini area. A short sortie from 1600 to 2040 into the lagoon was made by the Estes, Curtiss, and Belle Grove in order to use the Belle Grove's boats to exchange passengers. Reentry to the lagoon was made at 0815 on 6 May. The Curtiss departed that evening for Enewetak, landing CTG 7.3 at Parry Island the following morning (Reference 14, pp. 174-175). Lagoon water movement to- ward the Southwest Passage substantially increased radiation levels in the Enidrik-Bokdrolul area. The YANKEE fallout pattern is shown in Figure 90. Two LSTs, 762 and 975, en route in company from Enewetak to Hawaii, encountered the fallout cloud about 700 nmi (1,300 km) east-northeast of ground zero at H+35 to H+41. LST-762 was equipped with standard task force washdown equipment, but LST-975 had only standard firefighting equipment. At 12°S6'N, 176°51'E at 1300 on 6 May, radiation intensities of 0.015 306