brought aboard ship, as opposed to any instruments housed within the can. The intensity of the lagoon water in the recovery area was 500 mR/hr andthat ofthe instrumentcan itself, 1200 mR/hr (Reference 12). This was the only attempt to recover any instrumentation in Area Dog on 27 April. The contaminated can wastransferred to YC-1081 in the Nan anchorageat approximately 1820 hours, 27 April. It is estimated the crew was exposed to “shine” from the contaminated lagoon water for approximately 1.2 hours while in Area Dog. Assuming a topside intensity 40 percent of the water intensity, crewmen topside on COCOPA during Project 1.4 recovery operations on 27 April received an integrated exposure of approximately 240 mR due to shine from contaminated water. COCOPAcontinuedassisting in Project 1.4 recovery operations in Area Dog on 29 and 30 April, and again on 1 May. Although lagoon water intensities in the recovery area had significantly decreased due to radioactive decay and diffusion, continued operations in the contaminated water had led to a buildup of significant radioactive contamination on COCOPA's exterior hull below the water line and in the saltwater piping (Reference 12). In order to reduce the ship contamination problem, COCOPA departed Bikini Lagoon for sea at approximately 1800 hours, 1 May, where it steamed in “clean” water until 0630 hours the following day. This method of decontaminating the ship's exterior hull and internal saltwater systems was employed by many of the support ships at Operation CROSSROADin 1946 whenit was found that steaming in clean water outside of the lagoon reduced the accumulated contamination by abouthalf during the first day after leaving the lagoon, but that subsequent steaming had a much smaller effect (Reference 4). After returning to the lagoon on 2 May and anchoring near TAWAKONT, the captain departed the ship for approximately 1 1/2 hours; it is assumed he made arrangementsfor transfer of Project 1.4 support to TAWAKONIatthis time (reported in Reference 12 as being necessary due to accumulated contamination of COCOPA). On 3 and 4 May, COCOPAvisited Area Fox in the northern lagoon (see figure 2.1), whereit likely assisted TAWAKONIin final preparations for Project 1.4 participation at Shot YANKEE, scheduled for 5 May. At approximately 1600 hours, 4 May, COCOPAdeparted Bikini enroute to its assigned operating area for the YANKEEdetonation. Shot YANKEEwasdetonated at 0610 hours, 5 May. Fallout and contaminated lagoon water resulting from Shot YANKEEsignificantly increased radiation levels in the vicinity of the - Nan anchorage area off Eneu Island. Consequently, COCOPAdid not return to the lagoon until approximately 0800 hours on 6 May. By this time, intensity levels of the water in the anchorage 36