Gold bars cool after being removed from their moulds after refining at the Kaloti Jewellery LLC factory in Sharjah, United Arab Emirates, on Sunday, June 30, 2013. XXX ADD SECOND SENTENCE XXX. Photographer: Duncan Chard/Bloomberg

Rome - Captain Robert Mayne stands at the wheel as he guides the steel-hulled Aqua Quest from the docks in the Florida Keys, pointing the vessel towards what he has been assured is a gold-laden shipwreck that may be worth tens of millions of dollars.

Mayne, 60, says experience has taught him such gold hunts can be perilous: inspiring obsession, sending treasure hunters on endless journeys and blinding them to reason.

“Gold makes people crazy,” says Mayne, who in his youth smuggled marijuana. “They become lost in their dream.”

Even he finds the pull irresistible. Investors who hold rights to the site southwest of Key West say it may be the resting place of a galleon sunk by a 1622 hurricane. Mayne has agreed to cover the cost of the excursion in exchange for half of any treasure.

Gold’s draw is a powerful one that drives dreams and financial markets. It helped create a bubble in global gold prices, which gained more than sevenfold over a 12-year period. After peaking at $1 921.15 an ounce in September 2011, the precious metal fell to as little as $1 180.50 in June. It gained $13.50 to $1 286 (R13 297) at yesterday afternoon’s fix in London.

The drop is denting fortunes, from individuals who bought coins in television offers to billionaires who bet wrong. The gold fund of John Paulson, the New York hedge fund manager, declined 62 percent this year through September.

Yet for treasure hunters, the recent drop hardly makes a dent in their ambitions. Gold prices are higher than when they began their quests, years or decades ago.

The 65-foot Aqua Quest and its crew of salvage divers chug into open seas, the Gulf of Mexico to their right and the deep Gulf Stream far to their left. The water ahead is pale blue, like in holiday brochures.

The investor who struck the exploration deal with the firm Mayne founded, Aqua Quest International, is Kenny Rose, 69, a retired real estate agent and former bartender who has spent 33 years looking for the wreck. He began his search after a chance meeting with a man on the Key West waterfront who had a treasure map.

Rose and other investors have poured $1.23 million into the hunt over the decades. They owe $320 000 in legal fees for securing rights to the site.

“I started when I was a young guy. You want to get famous. You want to do something with your life. Wine, women and song,” he says.

The moustached Rose rattles off the specifications of what the divers should be prepared to find. “Twenty-three tons of silver, 22 bronze cannons. Hundreds of pounds of gold.”

A sheaf of papers, he says, holds evidence he is on the right track, including sonar scans that indicate the site, 15m down, is encased in the remains of wood worms.

The US treasure hunting industry ranges from small operators like Rose to Key West’s Mel Fisher’s Treasures, known for finding the 1622 Spanish Atocha wreck in 1985, to Tampa-based Odyssey Marine Exploration, with a market value of about $180m.

The gold is there, found through the combined resources of archival research, hi-tech tools, luck and obsessive persistence.

For Rose, his search has become about “vindication, that I didn’t waste my life chasing this treasure, that there is something there”.

At 4pm on day four of the expedition in July last year, Mayne surfaces from his last dive. “There’s no sign of a shipwreck.” The Aqua Quest’s expedition is over.

Rose keeps going. “After 33 years, I’m not quitting.”

In September, Rose tries a device that uses radio waves pointed at the surface of the water. He says it sensed possible gold and silver in the area.

“Things are flowing along as we ready our new workboat,” he says via e-mail. “The beat goes on.” – Bloomberg