Around 150 metres below the water's surface, west of the Norwegian island of Fedje, a fragment of German wartime history lies on the seabed. A submarine called U-864 has been resting there for more than eight decades, broken into two parts, surrounded by sediment and a cargo that still poses an environmental problem today.
U-864 is an exceptional case: according to historical records, large quantities of mercury were probably on board, with a Japanese order mentioning 1,867 containers.
