U.S.-based underwater salvage and exploration company Odyssey Marine Exploration announced Monday that it pulled more than 61 tons of silver bullion worth about $36 million from a World War II British cargo ship.

The torpedoed ship rested about three miles below the ocean surface, making the haul the deepest and largest precious metal recovery from a shipwreck, according to Odyssey. The 412-foot SS Gairsoppa sunk in 1941 about 300 miles off the coast of Ireland after it was attacked by a German U-boat.

The wreck included 1,574 silver ingots that weighed about 1,100 ounces each. The 1.8 million ounces of silver are being stored in a secure facility the U.K. Including silver recovered in a 2012 expedition, Odyssey as pulled 2,792 ingots from the ship. That represents more than 99 percent of the silver that was recorded on the ship when it sank.

The company’s contract with the UK Department for Transport allows Odyssey to retain 80% of the net value of the cargo, according to Odyssey. The contract was awarded to Odyssey following a competitive tender process.

The company recovered the silver using remote vehicles. Odyssey said. It was a complicated recovery because some of the silver was stored in a small compartment that was difficult to get to. The remote vehicle took more three and a half hours to reach the ship. Reported Discovery News.

“The ability of our team to deliver on our planned objectives underscores our experience and the tremendous determination of our team. We have accomplished a world-record recovery at a depth never achieved before. We’re continuing to apply our unique expertise to pioneer deep-ocean projects that result in the discovery and recovery of lost cultural heritage, valuable cargoes and important and needed natural resources,” Mark Gordon, Odyssey’s president and chief operating officer said in a release.

Photo courtesy of Odyssey Marine Exploration, Inc., www.odysseymarine.com