As shipwrecks of World War II continue to erode in the sea, their toxic cargoes continue to pose a catastrophic threat. Now, experts use cutting-edge tech to investigate and reveal the potential impact of these noxious underwater dangers. Examined are: Operation Davy Jones' Locker: the Allied post-war sea disposal of captured German chemical weapons; the SS Richard Montgomery, a Liberty ship sunk in the Thames Estuary, near Sheerness, England with 1,500 tons of explosives; and the Norwegian SS Skytteren scuttled off Måseskär, Sweden with 170 tons of oil on board.