Discussions of the lagoon contamination following Shots BRAVO, UNION, and YANKEE, and pertinent assumptions concerning these environments, are as follows: Shot BRAVO Documentation (e.g., Reference 1) indicates that the water throughout the lagoon became contaminated by BRAVO plus three days (4 March); however, little is known of the water intensity levels. Therefore, it is assumed that ships entering the lagoon on or after 4 March became contaminated to the saturation level one day after entry into the lagoon. Shot UNION The water contamination in the vicinity following this shot. of the anchorage However, area was relatively free.of five days after the shot (1 May), messages indicate that lagoon contamination was presenting more of a problem. For the present analysis, it is assumed that contamination spread to the anchorage area five days after the shot, and ships that entered the lagoon on or after 1 May reached a saturation level of contamination after one day of exposure to this water. t Shot YANKEE Documentation indicates that the water in the anchorage areas became contami- nated the day of Shot YANKEE (5 May). For this analysis, it is assumed that any ship entering the lagoon after the shot reached saturation if it remained there for a day or more. Also following Shot YANKEE, the SIOUX encountered contaminated water while steaming outside of the lagoon. The water intensities are recorded in detail in Reference 13 (see Figure 2-30). With this information, the full contamination model in Reference 6 is applied to calculate the crew's exposure. In order to demonstrate the inferred build-up and decay of the intensity below deck as a ship enters and leaves contaminated 31 water (the Bikini anchorages),