It was called the Baltimore Canyon, but it might just as well have been the Bermuda Triangle.

A rocky stretch of seabed paralleling the Atlantic Coast from Long Island to Virginia, the Canyon, in the late 1970s, was the hottest prospect in the oil business, the home of the Great Stone Dome, a geological formation said to hold 13.5 trillion cubic feet of natural gas, enough to keep homes and business in the Northeast warm for many winters.

Enthusiasm over the canyon's prospects spread north and south to two other areas -- Georges Bank, southeast of Nantucket, and the Georgia Embayment, off the Florida coast. If the hunches of oil company geologists were right, the oil and gas fields off the East Coast held enough petroleum to lift a large part of the yoke of imported oil off of the United States.

But like the Bermuda Triangle, the Baltimore Canyon -- and the other East Coast prospects -- swallowed up those hopes and dreams, as well as more than $3 billion in land-rights fees and drilling costs.

Over six years, oil companies drilled 46 holes into the seabed hundreds and even thousands of feet below the rolling Atlantic. A handful showed traces of petroleum; the vast majority were, in the oil industry's parlance of frustration, "dry holes."

Given the high cost of bringing any oil or gas found to shore and the declining level of petroleum prices in the first part of this decade, there was no point in trying to exploit any of the meager discoveries.

Most oil companies have let their drilling rights lapse on the nine-square-mile tracts of the Atlantic for which they paid as much as $108 million a tract, and the federal government's last attempt to sell leases on Atlantic Coast sites -- a group of tracts in Georges Bank -- drew not a single industry bid in September.

Last month, the drilling ship Discoverer Seven Seas pulled up anchor 79 miles east of Chincoteague and sailed away from the last well drilled in the Atlantic, still another dry hole. The Shell Oil-sponsored well will probably be the last attempt to find oil or gas off the East Coast of the United States until the next decade -- if at all.

"If you had a lease sale today, probably nobody would show up," says Henry Hill, manager of offshore and Alaskan exploration for Conoco, the oil company owned by E. I. du Pont de Nemours & Co. Inc.

Hill, who enthusiastically directed Conoco's pioneering efforts to find oil off the East Coast, now says, "It was a new area, good-looking prospects, and it turned out to be dry . . . It did not live up to industry expectations."

"It's a big disappointment," said Stephen Chamberlain, director of exploration at the American Petroleum Institute, an industry group.

"For the foreseeable future, I can't imagine anyone throwing anymore money down dry holes out there," says Sanford Margoshes, an oil-industry analyst at Shearson Lehman American Express. "The word I would use to characterize it is failure."

In retrospect, some in the oil industry say, maybe the Atlantic Coast's oil prospects were overrated, the product of hype by the industry, the financial community and the press, all looking for a big East Coast oil discovery to throw in the face of the Arab oil sheiks. "It was an excruciatingly exciting idea that you could find oil and gas in proximity to the end user," Margoshes says. "But I think the people who got too excited were simply carried away."

In the charged, energy-conscious era of the late 1970s, the possibility that there was oil or natural gas in the Atlantic Ocean was big news. Drill ships and spider-like semi-submersible drilling rigs dotted the ocean a hundred of miles or so off the New Jersey coast, support bases sprung up in New Jersey and Rhode Island, and commentators were fond of likening the search to the gambling industry then getting under way at Atlantic City, where many of the roughnecks who worked the oil rigs played when they weren't pushing drillstick 15,000 feet and more into the earth.

The fairly unexciting auctions of leases in the Baltimore Canyon drew television network coverage (one auction even had to be held in Madison Square Garden's Felt Forum to accommodate the crowd). The discovery of a small amount of gas in the Canyon by Texaco Inc. in the summer of 1978 was a major news event; a couple of months earlier, a false report about a discovery of gas by Conoco sent the company's stock soaring before it was denied. "Wall Street wasn't that far away, and everybody's eyes were on it," says First Boston Corp. analyst William Randol. "It was right in everybody's back yard."

The excitement over the region's petroleum-bearing possibilities was not entirely groundless. It was based on some very exciting geological indicators, particularly rock types and the existence in the Baltimore Canyon area of the Great Stone Dome that could have acted as a giant underground oil tank.

"Those type of rocks . . . tend to be a giant field when you find something in there," Hill says. "If it had anything there, it had a chance to be a giant oil field."

"There was nothing wrong with the geology before they drilled into it," Chamberlain says.

When the government first put sites in the Baltimore Canyon up for lease in 1976, the prime tract -- right at the apex of the dome -- brought a bid of $108 million from a group of companies including Mobil Corp., Marathon Oil Co., Sun Oil Co. and Amerada Hess Corp. Neighboring tracts went to those and other companies for prices like $75 million, $65 million and $60 million. In all, 38 companies paid the government about $1.4 billion for the right to drill in the Baltimore Canyon.

But the dry holes came fast and furious, and it became clear that the Great Stone Dome contained nothing but stone. That knowledge did not come cheaply: Exxon spent $117 million -- not counting lease costs -- to drill seven wells that turned up nothing but rock and dirt; Texaco spent $77 million on five wells that only produced two tiny discoveries of natural gas. In all, oil companies invested $1.75 billion in the Baltimore Canyon and came away with virtually nothing to show for it.

It is a measure of the frustration and irony of the Baltimore Canyon that one of the few wells that did find traces of petroleum was a drilling test intended to bring up only geological information. While oil wells were bringing up nothing but dirt, this dirt well brought up oil -- but not enough. Like all the others, it was ultimately capped and abandoned.

By 1980, interest in the Baltimore Canyon was waning, shifting to other, more promising sites. One was not far away, the Georges Bank area off Cape Cod. Georges Bank was, if anything, more of a disaster than the Canyon. Vehemently opposed by environmentalists who feared that an oil spill could wreck New England's most fertile fishing grounds, drilling in the Georges Bank was held up in court for years, and one lease sale was disrupted by demonstrators who threw motor oil and fish at the oilmen.

Once the oil companies did drill in Georges Bank, albeit on a limited basis, they found that the environmentalists had nothing to worry about -- there was no oil there. Eight wells were drilled in the area, all dry holes. Total cost, including drilling rights: $1.2 billion.

Attempts to look for oil in the Georgia Embayment were similarly unsuccessful, and wells drilled on an area known as the Yellow Reef -- so named because that was how it was colored on U.S. Geological Survey maps -- brought tantalizingly small discoveries, but not enough to warrant the estimated $1 billion expenditure to put in producing wells and build a pipeline to shore.

The last few wells, drilled by Shell, were real long-shots -- pioneering attempts to drill in water deeper than the industry had ever operated before, off the edge of the Continental Shelf just south of the Baltimore Canyon. The final well was drilled in water a record 7,000 feet deep. There was nothing there, either.

If you talk to oilmen, they'll tell you that searching for oil or gas, particularly offshore, is about the same as looking for a needle in a haystack. The lore of the oil field is full of stories about wells drilled right next to dry holes that turned into highly successful producers. And everybody is fond of quoting the litany of failure that accompanied some of the most successful oil fields, like 15 dry holes that preceded the discovery of oil in Alaska's Prudhoe Bay, the 49 dry holes that came before the first strike in the Atlantic off Nova Scotia, or the whopping 212 unsuccessful attempts to find oil in Great Britain's North Sea (although natural gas was found there on the fifth try).

By comparison, the 46 abandoned wells off the Atlantic Coast don't look quite so bad. "Companies never write off an area with as relatively few wells as they have drilled in as relatively large an area," Chamberlain says. Certainly, nobody likens the Atlantic Coast fiasco to the Mukluk field in North Alaska, where a group of oil companies last year spent $1.5 billion on leases, the construction of an artificial island and one all-the-eggs-in-one-basket well on the most promising spot -- and found absolutely nothing. Still, the $3 billion-plus spent on exploration offshore in the Atlantic puts it in a similar league of failure.

The biggest boon to come from the Atlantic Coast exploration efforts may be the geological knowledge that can be reaped from failure and the technological experience of drilling offshore in deep water. "There were certainly technological gains," says J. C. Threet, vice president for exploration at Shell. "We can confidently drill in water depths of 7,000 feet in weather conditions like those experienced in the Atlantic."

"It's difficult not to learn something incremental when you go into a new area," Margoshes says. "Doubtless they learned something about drilling in deep water, and they learned something about the geology off the East Coast. Does that justify the huge expenditure? Of course not."

Nevertheless, many in the oil industry believe they will try again to find oil or gas off the Atlantic Coast, once the economics justify it and supplies of petroleum demand it -- perhaps in the 1990s. The companies continue to urge the government to make drilling rights in the Atlantic available -- although nobody seems to want to bid on them just yet -- and the oil explorers continue to maintain their characteristic optimism about the situation.

"It's like all the other wildcat major frontier areas . . . It takes quite a bit of determination and perseverence," said a Texaco spokesman. "Oil people are eternally optimistic. You just have to persevere."