Bikini Atoll · Marshall Islands · Wreck
Nagato
Four battleship propellers, upside down at 33.5 m
Area photo: Unknown author · Public domain
The Japanese battleship Nagato was anchored close to the Baker aim point so that the test would be certain to sink her, and even then it took five days: her list grew until she capsized during the night of 29/30 July 1946. She lies upside down in the lagoon, her four propellers standing 33.5 m below the surface and forming the landmark most teams navigate from.
Also known as HIJMS Nagato, Japanese battleship Nagato.
Where it is and how deep
No published position for this site — the map shows Bikini Atoll and its other sites; operators know the mooring.
The dive
Nagato is inverted, so nothing on this wreck reads the way a ship's plan does: the hull is the ceiling and everything else hangs beneath it. The four propellers are the most prominent feature of the wreck, standing 33.5 m below the surface, and they are the landmark teams come down onto before working along the 215.8 m of upturned hull. Orientation has to be established in the water rather than assumed.
That depth makes every visit a decompression dive. Bikini is run as a technical destination and charters carry a deco-bar to meet the atoll's requirements, so the plan is built around the stops as much as around the ship. Conditions do not vary much: the lagoon holds 27 to 29 °C all year with visibility over 30 m, and the season runs May through October. The Times named Nagato one of the top ten wreck diving sites in the world in 2007.
The wreck
- Vessel
- Nagato
- Type
- Battleship
- Length
- 215.8 m (708 ft)
- Built
- 1919
- Sunk
- 1946
- Cause
- Capsized five days after the Baker underwater nuclear test at Bikini
- Lies
- Upside down, her four propellers standing 33.5 m below the surface
Nagato was launched on 9 November 1919 and survived the war only to be taken as a target for Operation Crossroads. She came through the Able airburst, 1,500 m from ground zero, with light damage, so for the Baker underwater shot she was positioned near the aim point to guarantee her being sunk. Even then she stayed up: she carried a two-degree starboard list once the tsunami dissipated, the list grew over the next five days, and she capsized and sank during the night of 29/30 July 1946.
Marine life and season
The sources we used don't single out particular species here.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Fair | Fair | Fair | Good | Good | Good | Good | Good | Good | Good | Good | Fair |
Season follows Bikini Atoll: Charters run in the calmer Apr-Nov window; remote crossing logistics and permit scheduling limit trips outside this period. Residual radiation is monitored and considered low for dive visits.
Dive videos
Dive the wreck of IJN battleship Nagato, Bikini Atoll, Marshall Islands · GlostaKenshi on YouTube
Nagato 2014 Episode 3 - inside · FinnborgBraga on YouTube
Questions divers ask
How deep is the Nagato wreck?+
Her four propellers, the most prominent feature of the wreck, are 33.5 m below the surface. That is the only published depth for the site; Nagato lies upside down on the floor of the lagoon, so the rest of the ship sits deeper than that figure.
Why is Nagato upside down?+
The Baker underwater test left her with a slight starboard list that increased over the following five days until she rolled and sank during the night of 29/30 July 1946. She came to rest inverted on the floor of the lagoon.
Sources
- Japanese battleship Nagato — Wikipedia
- Operation Crossroads — Wikipedia
- Bikini Atoll — Wikipedia
- Ralik — Wikivoyage
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