On February 16, 1941, Ernst Mengersen, Captain of Nazi U-boat 101, torpedoed the starboard side of the British merchant ship SS Gairsoppa, sending her to the bottom of the Atlantic. Little did Captain Mengersen realize that the value of the sunken ship's cargo would be worth almost a quarter of a billion dollars seventy years later.

The wreck of the SS Gairsoppa was discovered 300 miles off the coast of Ireland, at a depth of 15,400 feet, by Odyssey Marine Exploration. The British Government had awarded an exclusive contract to Odyssey to find the SS Gairsoppa which, on her last voyage, was returning from India with a cargo of pig iron, tea and 7 million ounces of silver ingots.

The silver treasure, which is the largest value cargo salvage in history, was originally valued at approximately £600,000 British pounds when the SS Gairsoppa was sent to the bottom of the Atlantic. Those 7 million ounces of silver today are worth 225 times the 1941 value or about £136,000,000 ($210 million).

The 412 foot steel-hulled SS Gairsoppa had been in service since her construction in 1919 and was sailing with a convoy to England on what turned out to be her last voyage. Running low on fuel and in a heavy storm, the unlucky ship left the convoy to head for Galway, Ireland. After being spotted by a German plane, the Gairsoppa's fate was sealed as U-101 moved in for an easy kill.

Although the general location of the sunken ship was long known, the technical complexity of salvage operations at a depth of 4,700 meters made recovery operations almost impossible. Recent advances in salvage recovery, as well as the increased value of silver, resulted in the British government soliciting private companies to find and salvage the Gairsoppa's precious cargo. Under the agreement with the British government, Odyssey Marine will keep 80% of the value of the silver bullion recovered.

SS Gairsoppa - courtesy Odyssey Marine Exploration

Odyssey Marine has gained fame for previous discoveries of sunken ships laden with gold and silver treasure. In 2003 Odyssey discovered the SS Republic, a Civil War era ship with over 50,000 silver and gold coins on board. Odyssey also recovered a treasure trove of over 500,000 silver and gold coins from a Colonial era shipwreck site code named Black Swan.

Of the hundreds of thousands of shipwrecks over the centuries, the only cargo worth retrieving (other than archaeological treasures) are precious metals, which have retained value since the dawn of human civilization. Just for laughs, let's compare that to the purchasing power of the paper dollar over the past half century.