81 years after British submarine sank Nazi U-boat, Norway faces mercury threat from its wreck

In February 1945, the British submarine HMS Venturer sank the German U-boat U-864 off Norway’s Fedje island, killing all 73 people aboard. More than eight decades later, the wreck has become the centre of a very different problem: a potentially massive mercury cargo that remains on the seabed. In June 2026, Norwegian authorities recovered 22 mercury containers from the wreck during an underwater investigation, as per a report by Diario AS.According to Norway’s Coastal Administration, Kystverket, a wartime Japanese order found in British archives referred to 1,867 mercury containers intended for U-864. If the entire shipment was loaded, it would have amounted to between 65 and 67 tonnes of metallic mercury. However, there are no surviving loading documents that confirm exactly how much mercury was actually aboard when the submarine sank.The submarine’s final missionU-864 was a German Type IXD2 submarine that was travelling from Germany via Norway towards Japan during the final months of World War II. Its mission, known as Operation Caesar, involved transporting specialists, military equipment and materials intended to support Japan’s wartime industry.Among the cargo was mercury, a s...