(FORTUNE Magazine) – Just like today's most sophisticated pirates, yesterday's used an underground banking system to hide their loot. This system was literally underground, of course, and spadefuls of doubloons still turn up from time to time along the beaches of the Caribbean and America's East Coast. Lee Spence, professional treasure hunter, believes a few choice troves are still waiting to be found, including Blackbeard's very own 401(k) -- probably buried somewhere in North Carolina. But the granddaddy of all hoards could be resting at the bottom of a 200- foot shaft on Oak Island, off Nova Scotia. This so-called Money Pit has exercised a moth-to-flame attractive power over investors since it was discovered in 1795. Even Franklin Roosevelt -- as a goatish, pipe-smoking 27- year-old -- invested in the search firm of his day, Old Gold Salvage & Wrecking Co., and went to the island to help dig. The Pit, however, has resisted Old Gold's and every other effort. At the 90- foot level, explorers discovered a cross-tunnel that let in seawater, flooding the works. Another tunnel at 150 feet did the same. These structural booby traps, plus such artifacts as an encrypted stone whose message reads (in one translation) ''40 feet below, two million pounds lie buried,'' have led archaeologists, mining engineers, and hopeful persons in general to believe the Pit was designed by someone very clever in order to hide something very precious. Most suspect a pirate, hiding pirate treasure. Sir Francis Drake might be the man. His treasure: New World gold plundered from Spain's galleons. That, at least, is the theory of David Tobias, president of Oak Island Exploration Co., the Pit's present owners. Shares in this company are listed in the National Quotation Bureau's Inter-Dealer Daily Quotation Sheets (a.k.a. the Pink Sheets). The asking price stands at 75 cents. There are no bids at present. To get Drake's gold -- or whatever is down there -- will take, by Tobias's estimate, $10 million, which would pay for sinking a watertight steel caisson, 80 feet in diameter, to a depth of 215 feet. First step: Raise $10 million. Though 20 underwriters expressed interest in helping back in 1987, the subsequent market crash left them Pit-shy. Tobias's new plan is to presell television rights to the dig. He envisions a TV special along the lines of 1986's The Mystery of Al Capone's Vaults. This depicted a minute-by-minute attempt to pry open a concrete cupboard believed to have once belonged to Scarface himself. Two hours and many commercials later, workmen broke through to discover empty whiskey bottles. No matter. It was the highest rated syndicated television special of all time.