Prinz Eugen

The Prinz Eugen is the odd survivor's story of Operation Crossroads. The German heavy cruiser — Bismarck's consort in 1941 — rode out both 1946 blasts at Bikini, was towed to Kwajalein Atoll for study, and capsized there that December. She still lies where she rolled, upside down on a slope with her stern section near the surface; for decades a propeller shaft and rudders broke the water before one screw was recovered to Germany as a memorial. Divers who obtain access work along the inverted hull past torpedo tubes, guns, and the armor belt of one of the last intact heavy cruisers anywhere.

The moment you come for: An essentially complete WWII heavy cruiser; torpedo tubes and armament visible along the hull; naval history stacked from surface to sand.

Topography: Capsized hull on a shallow lagoon slope, stern near the surface and bow deeper

Entry: The ship lies in Kwajalein Atoll, not Bikini's lagoon; access runs through operators and US Army Garrison arrangements and is not open on demand.

Hazards: Inverted overhead spaces with collapsing internals; restricted and changeable access arrangements; fuel and munitions history in the hull.

Conservation: A US-titled war memorial wreck in Marshallese waters; oil was removed in a 2018 operation, and disturbance of the hull or fittings is prohibited.

Nitrox: Worth it here — profiles sit in the range where enriched air meaningfully extends no-stop time (with the training to use it).