Watch Movies2Watch. In Summer 2008, a mysterious submarine, German U-boat U-455 is discovered off the coast of Italy at 120 meters deep. For Lorenzo del Veneziano, an underwater marine archeologist, it's an amazing sight. The U-boat is intact! It stands almost vertically at the bottom of the sea, it's hull stuck in the sediment. What is the story of this ship? The history of U-455 & cause of the sinking are revealed.