So treasure hunting does pay off. U.S. exploration firm Odyssey Marine has announced the largest precious-metal haul ever discovered at sea in the shipwreck of SS Gairsoppa, a British cargo ship sunk by a German U-boat in 1941. Only one person from the 85 crew members survived the torpedo attack during the Second World War. The deep-sea treasure contains 200 tons of silver, and the firm gets to retain 80 percent of it under a contract with the Department of Transport. The wreck was found this summer some 15,000 feet below the North Atlantic just off the Irish coast.