The Daigo Fukuryū Maru encountered the fallout from the U.S. Castle Bravo nuclear test at Bikini Atoll, near the Marshall Islands, on March 1, 1954. When the test was held, the Daigo Fukuryū Maru was catching fish outside the danger zone which the U.S. government had declared in advance. However, the test was more than twice as powerful than it was predicted to be, and changes in weather patterns blew nuclear fallout, in the form of a fine ash, outside the danger zone. On that day, the sky in the west lit up like a sunset. Seven minutes later the sound of the explosion arrived, with fallout reaching the ship two hours later.[better source needed] The fishermen realized the danger, and attempted to escape from the area, but they took time to retrieve fishing gear from the sea, exposing themselves to radioactive fallout for several hours.
The fallout – fine white flaky dust of calcinated Bikini Island coral, which absorbed highly radioactive fission products and neutron activated isotopes – fell on the ship for three hours.[when?] The fishermen scooped it into bags with their bare hands. One fisherman, Matashichi Oishi, reporting that he “took a lick” of the dust that fell on his ship, describing it as gritty but with no taste. The dust stuck to surfaces, bodies and hair; after the radiation sickness symptoms appeared,[when?] the fishermen called it shi no hai (死の灰?, death ash).
The bald head of one of the crew on 7 April 1954, focusing on the burn and general skin discoloration.