Twenty fathoms beneath the waters of Lough Swilly, a glacial fjord off the coast of Ireland’s County Donegal, lies more than $10 million worth of gold.

That’s all that remains of a massive cache of sunken treasure lost during World War I on the HMS Laurentic, an armed British merchant cruiser that struck two mines and sank on January 25, 1917.

The Laurentic was ferrying more than 3,200 individual gold ingots, weighing in at around 44 tons and valued by the Bank of England at nearly £5 million ($25 million, or about $1.7 billion in today’s dollars) from Liverpool to Halifax, Nova Scotia. The cash-strapped Allies had assembled the gold to purchase arms and supplies from the United States.

Only 121 of the 475 officers, crew and passengers aboard the Laurentic survived the sinking; the majority died of exposure after being tossed about in lifeboats in the rough waters near where Lough Swilly opened into the Atlantic Ocean. The badly damaged ship descended some 120 feet underwater, along with its haul of gold.

The quest to find the Laurentic’s valuable war chest has lasted for more than a century, according to Joseph Williams, author of “The Sunken Gold,” the first full-length account of the salvage effort. While researching his book, Williams tracked down an unpublished memoir written by Lieutenant Commander Guybon Damant, the man who led the original hunt for the gold and persisted even after the Navy was ready to abandon it.

Desperately hoping to keep the sunken treasure’s existence a secret—especially from the Germans—the British Admiralty summoned the 35-year-old Damant to Whitehall in London in early 1917. Regarded as an expert in deep-sea diving, Damant had helped develop a safe decompression method to prevent the divers’ ailment known as the bends, and had worked as an inspector of diving for the Royal Navy.

A recompression chamber was also known as the “diver’s oven.” This was the first chamber used during the Laurentic operation and would later be replaced by larger models. (Credit: Journal of Hygiene 25, no. 1 (1926), courtesy of Cambridge University Press)
A recompression chamber was also known as the “diver’s oven.” This was the first chamber used during the Laurentic operation and would later be replaced by larger models. (Credit: Journal of Hygiene 25, no. 1 (1926), courtesy of Cambridge University Press)

Once his team located the wreck in March 1917, the real work began. Braving the ever-present possibility of attacks by German U-boats, divers used crowbars to pry open boxes and cleared debris that blocked passage into the interior of the ship. By mid-March, they had made it to a barred iron gate, which marked the entrance to the ship’s strong room. Excitement mounted as lead diver Ernest Charles “Dusty” Miller pried open the door to the baggage room and slid down a passageway—straight into a pile of boxes containing the gold.

Miller and the other divers began slowly transporting the gold bricks to the surface. But they managed to raise only a few of the boxes before stormy weather halted the work. By the time the divers were able to return to the Laurentic in early April, they found it in an entirely different condition.

“When they get back, they find that the wreck’s been crushed like an accordion,” says Williams . “They try to access the gold room again by the same route, but because everything got crushed, what was once a 9-foot-high clearance has been crushed down to a few feet.”

Damant’s team used explosives to blow open the corridors inside the wreck, eventually reaching the strong room where they had last seen the gold. “Then all of a sudden, they hear the diver over the telephone wire, saying ‘The gold’s not here, sir. The deck is full of holes!’” Williams recounts. “The whole thing got ripped apart, and the gold just tumbled down deeper into the wreck. They knew they were in for a long slog after that.”

Damant’s team worked throughout the summer of 1917, and by early September had recovered a total of 542 gold bars of the original 3,211, with an estimated value of £836,358 in 1917 currency, according to Williams. At one point, a diver became trapped underneath a massive plate on the ship’s deck; in an excruciatingly close call, another diver managed to rescue him.

These illustrations show the Laurentic as the divers originally found it (left) and what it looked like after the storms. (Credit: Journal of Hygiene 25, no. 1 (1926), courtesy of Cambridge University Press)
These illustrations show the Laurentic as the divers originally found it (left) and what it looked like after the storms. (Credit: Journal of Hygiene 25, no. 1 (1926), courtesy of Cambridge University Press)

Then the Admiralty sent word that work was to be suspended. Germany’s pursuit of submarine warfare was devastating the British Navy. Britain’s new head of Naval Intelligence, Rear Admiral William Reginald “Blinker” Hall, called on Damant to lead a diving team tasked with salvaging sunken German U-boats (some surrounded by still-live mines) to locate cipher books, minefield maps and anything that could help the Allies defeat the underwater menace. The team explored at least 15 different wrecks, and found intelligence materials in about half of them.

After the Great War ended in November 1918, Damant had to convince the Navy to continue with the Laurentic’s salvage rather than hand the rights over to a private company. In May 1919, he and his divers returned to Lough Swilly to find that the wreck had not shifted position much since 1917. Though the divers managed to locate the gold again, they were turning up only a few bars at a time. Damant later realized the bulk of it had most likely slipped out through the hole created by the mines that sank the ship.

By late 1924, despite various obstacles, the team was able to retrieve more than 1,000 additional bars, bringing the total gold recovered since 1917 to more than 99 percent of the total cache.

Only then did Damant advise the Admiralty to abandon the project, admitting the value of the remaining 25 bars would likely not justify the effort necessary to find them. In honor of his success, Damant was made a commander of the Order of the British Empire (CBE).

Lough Swilly from Portsalon, County Donegal, Ireland. (Credit: Aaron Fink/Alamy Stock Photo)
Lough Swilly from Portsalon, County Donegal, Ireland. (Credit: Aaron Fink/Alamy Stock Photo)

By the early 1930s, the British Admiralty had signed over salvage rights to a private company, whose divers recovered a grand total of five gold bars. “They were banking on being able to go down there, find it quickly, and that would pay for everything,” Williams says. “But that wasn’t the case.” Efforts made in the 1950s by another salvage company came up with some valuable scrap metal but no gold. Then in the late 1960s, a pair of brothers named Ray and Eric Cossum decided to search for the Laurentic wreck themselves, having grown up hearing stories about it while vacationing with family near Lough Swilly. They dived repeatedly on the wreck until the early 1970s, but failed to come up with any gold.

Over the years, occasional reports have surfaced of the Laurentic’s sunken gold being found, but all of them appear to have been false. “There’s 20 bars of gold still left down there for anybody who is willing to spend the time and effort to find it,” Williams says. “It’s probably underneath the ship itself, so you’d have to clear out the whole wreck to get at it.”

Williams estimates those 20 remaining gold ingots would be worth some $10.7 million today—if you can get to them, that is.

When Williams got in touch with one-time treasure hunter Ray Cossum while writing his book, “One question I did ask him was ‘So, do you know where the gold is now?’” he recalls. “He said, ‘If I told you, everyone would be diving on the wreck.'”