An oceanic exploration company has recovered 122,000 pounds of silver from a shipwreck 300 miles off the coast of Galway, Ireland—the heaviest amount of precious metal ever retrieved from a shipwreck.

In February 1941, the S.S. Gairsoppa, a 412-foot steel-hulled British cargo ship with stockpiles of tea, iron, and silver, was weathering a storm when it was struck by a Nazi torpedo. The ship sank within 20 minutes; only one person survived.

At the time, the silver that ended up on the seafloor was insured at $1.3 million. Today it's worth about $75 million.

Going Deep

The silver was retrieved about two weeks ago by Odyssey Marine Exploration, which used a remotely operated vehicle to access the shipwreck. The vehicle descended about three miles and explored several rooms in the ship until it found the silver in two locations. (Related: "Deepest Shipwreck Explored Off U.S. Yields Treasures.")

Mark Gordon, president of Odyssey Marine Exploration, said the process of uncovering the silver at that depth was complex and difficult.