# Environmental risk from German U-864 wreck in Norway

> Live situation record from CLSTR: https://clstr.news/situations/environmental-risk-from-german-u-864-wreck-in-norway
> Updated: 2026-09-21T12:28:02.000Z. Sources: 17. Developments: 2.

The wreck of the German World War II submarine U-864, located approximately 150 meters below the surface off the Norwegian island of Fedje, has been identified as a significant environmental threat. The vessel is believed to be carrying between 65 and 67 tonnes of mercury in 1,867 containers, intended for the Japanese armaments industry at the time it was sunk in 1945.

Investigations by the Norwegian Coastal Administration (Kystverket) using remote-operated vehicles have shown advanced hull degradation, with reports indicating that up to 80 percent of analyzed containers are actively leaking mercury into the sediment. This creates a risk of the metal entering the marine food chain as methylmercury.

Authorities are currently evaluating two responses: attempting to recover the material or constructing an underwater sarcophagus using sand and rock to enclose the wreck. Experts have cautioned that recovery efforts are highly risky, as any movement of the corroded hull could trigger explosions from remaining torpedoes, potentially causing a more widespread release of toxins.

## Claims

- The German submarine U-864 rests 150 meters deep off the Norwegian island of Fedje. (single source)
- The U-864 contains between 65 and 67 tons of mercury in 1,867 containers. (single source)
- The British submarine HMS Venturer sank the U-864 on February 9, 1945. (single source)
- The Spanish Navy launched the Poseidón, a Maritime Action Vessel for Underwater Intervention (BAM-IS). (single source)
- The Poseidón will utilize the Hugin 6000 autonomous underwater vehicle from Kongsberg. (single source)
- Anduril manufactured the Seabed Sentry, a wireless underwater detection system tested by the US Navy. (single source)

## Timeline

### 2026-09-21: Maritime technology and environmental risks emerge in deep-sea operations

Maritime news highlights Norway's struggle with mercury in the sunken U-864, Spain's launch of the Poseidón rescue vessel, and the US Navy's testing of Anduril's Seabed Sentry underwater detection system.

3 sources. https://clstr.news/cluster/maritime-technology-and-environmental-risks-emerge-in-deep-sea-operations

### 2026-09-19: German U-864 wreck off Norway poses mercury leak risk

The sunken German submarine U-864 off Norway's Fedje island threatens the environment with up to 67 tonnes of mercury. Authorities are considering an underwater sarcophagus to prevent toxic leaks.

14 sources. https://clstr.news/cluster/nazi-submarine-u-864-poses-mercury-leak-risk-off-norway

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Cite as: Environmental risk from German U-864 wreck in Norway. CLSTR, https://clstr.news/situations/environmental-risk-from-german-u-864-wreck-in-norway