Miami – A Florida treasure-hunting firm announced Monday the discovery in North Atlantic waters of the remains of the British freighter SS Gairsoppa, sunk by a Nazi submarine in 1941 with 200 tons of silver aboard.
Valued at £600,000, the silver would be worth £155 million ($241 million) at current prices.
The shipwreck was found at a depth of some 4,700 meters (15,400 feet) and about 480 kilometers (300 miles) off the coast of Ireland, Odyssey Marine Exploration, Inc. said.
The SS Gairsoppa sank after being torpedoed by a German submarine in February 1941.
If all of the silver can be salvaged, it would be "the largest known precious metal cargo ever recovered from the sea," the company said.
In 2010 the British government reached an agreement with Odyssey giving the company exclusive rights to salvage the treasure.
According to the contract, Odyssey will keep 80 percent of the value of all the silver ingots that are recovered.
"We've accomplished the first phase of this project - the location and identification of the target shipwreck - and now we're hard at work planning for the recovery phase," Andrew Craig, Odyssey senior project manager, said in a statement.
"Given the orientation and condition of the shipwreck, we are extremely confident that our planned salvage operation will be well suited for the recovery of this silver cargo," Craig said.
Neil Cunningham Dobson, Odyssey's top marine archaeologist, said that although records indicate that the lifeboats were launched before the Gairsoppa sank, "sadly most of her crew did not survive the long journey to shore."
"By finding this shipwreck, and telling the story of its loss, we pay tribute to the brave merchant sailors who lost their lives," he said.
The announcement of the find comes less than a week after a U.S. federal appellate panel reversed the order by a district court judge for Odyssey to hand over another large treasure to Spain.
Odyssey salvaged that treasure, valued at $500 million, off the Portuguese coast in the same area where the Nuestra Señora de las Mercedes, a Spanish navy frigate, was destroyed in battle in 1804.
Madrid says the treasure came from the Mercedes and that the vessel and its contents rightfully belong to Spain under the principle of sovereign immunity.