At sea, Hardt manages to free the German prisoners and they seize the ferry. The Royal Navy pursue them, but before they can catch up, the ferry is intercepted by Hardt's submarine, and Hardt's first officer, Lieutenant Schuster (Marius Goring) decides to sink it. As the U-boat surfaces and prepares to fire, Hardt realises it is his own submarine. He frantically attempts to signal them, but too late – the U-boat shells the ferry, which begins to sink. By this time the British ships have arrived, and they drop depth charges, destroying the fleeing U-boat. As Jill, the other passengers and the crew abandon the sinking ferry, Hardt realises all is lost, and chooses to go down with the ship.