Commemorative certificate issued to a Navy participant in Operation Crossroads, the first postwar atomic bomb testing, conducted at Bikini Atoll in the South Pacific, July 1-25, 1946. This certificate is for the second test, 'Baker', held on July 24 when a 23 kt bomb was exploded underwater, beneath captured enemy vessels and old American ships. The 9.25 x 12.5 in. certificate shows a B-29 flying over the test fleet, the archipelago of islands, U.S. flags, mermaids, etc., and displays a small original photo of the 'Baker' blast at center. This particular example was distributed to crewmen aboard the USS BENEVOLENCE, a Navy hospital ship. Fine condition. On 25 August 1950 while returning from sea trials, BENEVOLENCE collided with a freighter in heavy fog and sank within 15 minutes off San Francisco. 505 crew members were rescued and 23 died.