topside intensities of 25 mR/hr. Figure 3.5 depicts the topside radiation environment on COCOPA resulting from Shot ROMEOfallout. On 30 and 31 March, COCOPArecovered Project 1.4 instrumentcans in Area Charlie, returning to the Tare anchorage each afternoon. During theearly afternoon of 1 April, COCOPA got underway for Enewetak Atoll whereit arrived at 0700 hours, 2 April. When Shot KOON was detonated at Bikini on 7 April, COCOPAwasstill at anchorin Enewetak Lagoon. It got underway for Bikini at 1737 hours on 7 April, arriving there and mooring alongside YC-1081 in the Nan anchorage at 0925 hours, 8 April. Entries in the ship's log indicate activities associated with Project 1.4 instrument recovery in Area Charlie on 9 April, and instrument placementfor Shot UNION in Area Dog(see figure 2.1) from 10 to 15 April. At 1230 hours, 15 April, COCOPA got underway for its assigned operating area for Shot UNION which was scheduled for the following day. As previously mentioned (section 3.2), Shot UNION was delayed due to unfavorable weather and COCOPA returned to the Nan anchorage at approximately 2000 hours, 16 April. During the period 17-25 April, COCOPA madealmostdaily trips to Area Dog to maintain the Project 1.4 instrument cans in place for Shot UNION, which, due to continued unfavorable weather, was rescheduled for 26 April. At approximately 1730 hours, 25 April, COCOPA got underway for its assigned operating area for Shot UNION with YFN-934in tow. Shot UNION was detonated at 0605 hours, 26 April, and COCOPAreturned to Bikini and anchored in the Nan anchorage at 1843 hours the same day. At approximately 2100 hours, COCOPAexperienced the samelight fallout that several other ships in the Nan anchorage reported (see section 3.2). Average topside intensities on COCOPAleveled off at 2 mR/hr with a maximum intensity of 4 mR/hr being recorded at 2200 hours; the shipboard radiation environmentresulting from Shot UNIONfallout is depicted in figure 3.6. During the morning of 27 April, COCOPA was involved in decontaminating YCV-9 and YC-1081, the two Project 1.4 barges that were left in the lagoon for Shot UNION. At 1345 hours, COCOPA got underway for Area Dogto recover one ofthe Project 1.4 instrument cans that was moored approximately 1.3 nmi southwestof surface zero (Reference 12). Being a barge shot over relatively deep water, Shot UNIONsignificantly contaminated the lagoon waterin the vicinity of surface zero. The general drift of the surface water in the contaminated pool around surface zero was to the west and southwest, toward Area Dog (Reference 8). At 1538 hours the ship approachedtheinstrument can and, by 1640 hours, the instrument can was hoisted aboardthe ship which then departed Area Dog enroute to Nan. It is assumed that the instrument can itself was 33