Odyssey Marine Exploration, a leader in deep-sea salvage operations, announced today that its chartered recovery vessel, the M/V Seabed Worker, has left port and is heading to the North Atlantic to begin extracting millions of ounces of silver from two historic British shipwrecks torpedoed by German submarines in the world wars.The operation targets the SS Gairsoppa, sunk during World War II, and the SS Mantola, lost in World War I.
Historical records suggest the Gairsoppa carried up to seven million ounces of silver, while the Mantola held about 600,000 ounces—potentially totaling more than 240 tons of the precious metal. Odyssey discovered both wrecks in the third quarter of 2011 and performed initial reconnaissance dives earlier this year in March and April.
The projects are underway through contracts with the U.K. Department for Transport, following standard commercial salvage practices. Under the agreements, Odyssey will keep 80% of the net value of the recovered cargo after expenses are deducted. The cargoes were insured by the British government under its War Risk Insurance program at the time of the sinkings.
For the mission, Odyssey has leased the 291-foot Seabed Worker from Norway-based Swire Seabed AS. The vessel is outfitted with cutting-edge deep-ocean technology, including dual remotely operated vehicle (ROV) systems and a 100-ton active heave-compensated crane capable of handling depths exceeding 4,000 meters. Odyssey has also invested in custom tooling to precisely cut through the steel hulls and access the bullion holds.
“Modern steel wrecks like the Gairsoppa and Mantola demand advanced tools for surgical precision in cutting decks and extracting cargo,” said Mark Gordon, Odyssey’s chief operating officer and president. “After a thorough evaluation, we selected the Seabed Worker for its ideal capabilities, including space to store up to 300 tons of cargo below deck. We’ve assembled the right team and equipment to ensure a secure and successful recovery.”
Gordon added that Odyssey’s own vessel, the Odyssey Explorer, will continue archaeological work on the HMS Victory site in the English Channel, separate from the silver salvage efforts.
Swire Seabed specializes in subsea services such as inspection, maintenance, repair, and decommissioning, with a focus on deep-water operations. The company operates globally with vessels like the Seabed Worker and Seabed Prince. The Seabed Worker, an 88-meter multipurpose support ship, features accommodations for 66 crew, a Class 2 dynamic positioning system, a spacious deck, and specialized ROVs rated for depths up to 5,000 meters. For this 2012 salvage, it has been equipped with additional custom gear.
Odyssey Marine Exploration, based in Tampa, Florida, has pioneered deep-ocean exploration and recovery since its founding, blending archaeology with commercial salvage. The company has previously recovered artifacts and treasures from sites like the SS Republic and the Black Swan project.
If successful, the Gairsoppa and Mantola hauls could represent one of the largest deep-sea silver recoveries in history, providing a boost to Odyssey amid fluctuating precious metal markets. Operations are expected to commence upon the vessel’s arrival at the wreck sites in the coming weeks.
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This article was revised in September 2025 to improve clarity.
