History’s fifth atomic explosion. A standard Fat Man type Mk 3A fission bomb was used in test.

The bomb was encased in a watertight steel caisson, and suspended beneath landing ship LSM-60. Eight ships were sunk or capsized, eight more were severly damaged. Serious radioactive contamination of the lagoon occurred, radiation exposure at the surface near the detonation point amounted to a lethal 730 R in the first 24 hours. Bikini Island, some three miles from surface zero could not be safely landed on until a week had passed. As water falls back from the stem, it forms a dense highly radioactive cloud called the “base surge”. Stern of the USS Saratoga can be seen rising 13 meter (43 feet) on the crest of the first wave (28,6 meter/94 feet high). Waves 1,8 meter (6 feet) high were seen 22,000 feet (7 km) from the explosion.