2-8 en supplied data on radiation at loc:tions representing major battle stations; underwater GITR instrumentetion suppiied da°t.. on radiation in the water; and directionally shielded GITR stations mounted on deck supplied informztion on radiation from remote sources, Radiation histories were obtained or ony one destroyer during shot “lahoo, because of ship's power failures on the other two. Radiation historics were obtained on all three ships durin~ shot Umbrella, althouch some data was lost because of shock damaze. Preliminary results indicate thet weather-deck dose buildup ranged between 600 r received » thin 0.5 minute at 2,000 feet from surface zero and 45 r received wit*in 2 minutes at 8,000 feet. Dose reductions by factors less than 6 were sobtaiic2 for all compartments above the waterline, and dose reduction factors zreater then 9 were obtained only in machinery spaces below the waterline. Tronsit raciation appeared to re- present a high percentage of the t:-tal redierior observed ahoerd the ships. In the one case where the data was obtained, the underwater radiation did not contribute to the total radiation mezsured aboard snip. Data on gammae jonization decay was obtained for tn cercoc from 0.1 to 34.8 hours after Umbrella. Shipboard Contamination Inzress. This was a study of the external and in= ternal radiattion hazards. existing «itnin typical intcrior compartments of a cestroyeretype vessel as the result of the by underwater nuclear detonations. ..gress of contaminant from near- Four compartments of the DD-592 were instrumented witn total and tine-incremental eir samplers, surface samplers, animals (mice and guinea pigs), and GITR instrumentation. Rates of air flow for ventilation and boiler combustion for tre instrumented compartments were controlled so as to be representative of these expected under nuclear-attack conditions. a ras i hepS fg - "Due = to the failure of ship's rower on the LD-592 during shot ‘\iahoo, only Me Smee” PGE fk,