Bikini Atoll Sunken Nuclear Fleet

Mushroom-shaped cloud and water column from the underwater Test Baker nuclear explosion of 25 July 1946.During 1946, following the end of World War II, the US Navy gathered together a "mock" naval fleet for Operation Crossroads, to test the effects of atomic bomb blasts on naval fleets. The Pacific Proving Grounds site chosen for the explosive tests was Bikini Lagoon at Bikini Atoll and it was designated as a ship graveyard. Around the same time French fashion designer Louis Reard was looking for a name for his new, controversial, tiny swimsuit design and the "Bikini" was launched.

Map of Bikini Atoll with location of Operation Crossroads nuclear bomb tests.Operation Crossroads consisted of two detonations, each with a yield of 23 kilotons of TNT (96 TJ), the first nuclear testing done after the atomic bombing of Hiroshima and Nagasaki.

Test Able was detonated at an altitude of 158 metres (520 feet) on 1 July 1946. The ships sunk by this blast included: USS Gilliam attack transport, IJN Sakawa light cruiser, USS Carlisle attack transport, USS Anderson destroyer and the USS Lamson destroyer. A further 14 ships sustained serious damage.

1946 film showing US preparations for the Test Able atom bomb blast at Bikini Atoll. (3:17)

Test Baker was detonated 27 metres (90 feet) underwater beneath the landing craft LSM-60 on 25 July 1946. The ships sunk by this blast included: LSM-60 amphibious (no identifiable part of LSM-60 was ever found and it was presumed vaporised by the nuclear fireball), USS Arkansas battleship, USS Pilotfish submarine, USS Saratoga aircraft carrier, YO-160 yard oiler, HIJMS Nagato battleship, USS Skipjack submarine, USS Apogon submarine, and ARDC-13 drydock. The German heavy cruiser Prinz Eugen, sank in December 1946, five months after the test at Kwajalein Atoll, because radioactivity prevented repairs to a leak in the hull. Only nine surviving Test Baker target ships were eventually decontaminated and sold for scrap. The rest were sunk at sea after decontamination efforts failed.

1946 film showing the Test Baker underwater atom bomb blast at Bikini Atoll. (5:44)

During 1954, 1956, and 1958, twenty-one more nuclear bombs were detonated at Bikini Atoll, yielding a total of 75 megatons, equivalent to more than three thousand Test Baker bombs. The first after Operation Crossroads was the dirtiest: the 15 megaton Bravo shot of Operation Castle on 1 March 1954, the largest-ever U.S. test. Fallout from Castle Bravo test caused radiation injury to Bikini islanders who were living on Rongelap Atoll at the time.

Bikini Lagoon became the final resting place for some of the most significant warships in naval history. The dangers of the radioactivity and limited services in the area led to divers staying away from this most remarkable scuba diving site for many years. However, from the dust and detritus of the nuclear weapon tests, the lagoon at Bikini Atoll has emerged as the world's greatest wreck diving site. Bikini Atoll was first opened for limited diving in 1996, allowing divers to experience some of the most historic and amazing wreck diving in the world.

Video showing scuba diving at Bikini Atoll in the Marshall Islands, the site of the atomic bomb tests in the 1940s and 1950s. Credit: St Albans Sub-Aqua Club. (9:37)

See Bikini Atoll Nuclear Target Fleet for details about the Bikini Atoll nuclear target fleet and their final resting places.

Once diving at Bikini Atoll commenced in 1996, the dive spot quickly become popular among divers with around 200 visiting each year. However, oil prices and airline reliability then severely curtailed diving operations to the point of being suspended from August 2008 and through 2010, restricted to fully self-contained vessels by prior arrangement.

The Scuba Doctor's own Peter Fear, was a key member of a successful trial liveaboard expedition to Bikini Atoll in October 2010. Returning to Bikini Atoll for his third time on this dive trip, Peter was able to guide and assist the liveaboard operators in how to best conduct such diving expedition tours and the associated diving operations.

Bikini Lagoon contains a larger amount of sea life than usual, including sharks, due to the lack of fishing. This increases the fascination with the spot as a diver's adventure destination. Fish caught in the area is safe to eat, however food grown on the Bikini Atoll islands is contaminated and could be harmful if consumed over a long period, so dive expedition boats bring all of their own supplies.

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