You'd like Mel Fisher. Very friendly, very laid back. You can tell he's spent time in California.

And you can tell he lives in Florida now, by the way he dresses. He showed up here recently in an aqua-and-pink shirt, a tie and sport coat that were on the purplish side. And he had a gold doubloon around his neck. All sort of early Don Johnson. Very early.

But the fun part comes after you've shaken hands with him. That's when he likes to dip into his purplish coat pocket, pull out a three-foot gold chain and hang it around your neck. And before you've regained your balance, he's pulled out another and hung that one on you too. Is this real gold or lead in disguise? you ask, swaying under the weight.

"That one's 24 karat gold," he explained. "The Spaniards used to use it as money. They'd break off a link and it was like a hundred-dollar bill. They could buy a woman with it. The other one," he said, holding the chain with a slightly silver patina, "has some platinum in it. The two of them are worth about half a million dollars."

Welcome to the unreal world of Melvin A. Fisher, a world in which gold chains are treated like so many paper clips strung together.

If Fisher treats his golden horde casually, it's because there is so much of it, not because it came easily.

Fisher is the salvage expert who searched for 16 years for a Spanish galleon laden with New World treasures. It was heading back to the Old World with an escort ship in 1622 when a hurricane off the Florida Keys dispatched them both to the bottom, spilling and scattering one of the richest treasure stores imaginable.

Fisher's attempt to locate the lost ships, the Nuestra Senora de Atocha and its sister, the Santa Margarita, are chronicled tonight on "Quest for the Atocha," an hour-long segment of the two-hour National Geographic Explorer series at 8:05 on WTBS SuperStation.

"Atocha" is a milestone for the relatively new Explorer series. The show has aired on WTBS -- viewable locally via cable -- since early February. The series previously was carried by Nickelodeon, another cable programmer, but now basks in the wider viewership and heavier promotion afforded by Ted Turner's Atlanta SuperStation. In length and subject matter, "Atocha" is the most ambitious segment to be included in the series.

The documentary, narrated by Martin Sheen, chronicles Fisher's search, begun in 1968 when the former California chicken farmer and dive-shop owner started poking around for the Atocha off the Keys.

Five years later he found 1,500 silver coins, a first, small payoff, and one in a series of signs that he was looking in the right place. That same year he encountered legal problems with federal and Florida authorities.

And two years later his son, daughter-in- law and a crewman drowned when their boat capsized. Ten years later to the day that he lost his son, Fisher found what he refers to as the "mother lode," a major portion of the ship's treasure, a pile of silver bars so large it might be mistaken for a reef.

Fisher came to New York to discuss the show at a press conference, and he brought along a couple of chests of trinkets he'd hauled from the bottom. Men with bulges under their coats almost outnumbered reporters.

The display included a silver ingot, more gold chain, and assorted gold and silver vases, decanters and incense burners. Perhaps most eye-catching were a handsomely tooled, fluted gold dish and a stunning, four-inch enameled gold cross inlaid with a 50-carat emerald. There was a ring to match. "The display's probably worth about $5 million," said Fisher.

Fisher encountered some rough legal seas in salvaging the treasure. And frankly, not everyone thinks of him as a nice guy who deserves to have the haul all to himself. In the documentary, one official questions the propriety of such a collection remaining, basically, in private hands. "People try to tear you down or get jealous," said Fisher. "You just let it go in one ear and out the other."

Fisher tells stories about his encounters with state and federal officials with relish. He won, after all, but it wasn't easy. When the federal government indicated its interest in his find, he decided to meet the challenge head-on.

"I went to the attorney general's office with four lawyers," Fisher recalled. "When I walked into the room, they had 34 lawyers waiting for me."

Fisher said he offered the feds a $1.5 million share of whatever he found. It was refused. How about $3 million? No, thanks.

"Finally, I said, 'What do you want?' They said, 'We want it all.'

By Fisher's reckoning, it took eight years, 111 hearings, and $1.6 million in legal fees for him to win the right to the Atocha treasure. Ultimately the Supreme Court had to decide.

"We must have a pretty good government," said Fisher, "when a little guy like me can win."

The state of Florida was a bit easier to deal with. Fisher agreed to donate a cross- section of the treasure to museums if -- and he smiles telling this part -- if they would acknowledge the donation so he could write it off his federal taxes.

So far, he said, there are some 40 tons of Atocha treasure valued at about $200 million, recovered and displayed in Florida. A running estimate of the worth of the ship's cargo is around $400 million, and the ever-expansive Fisher, sounding like Carl Sagan, said it may go into the billions and billions.

The emeralds his crew is finding, for instance, are of special clarity, Fisher said. The largest they've found weighs more than 70 carats and may be worth nearly $2 million. About 70 pounds of the gems were supposed to have been aboard the Atocha, he said, and they've recovered only some 300 of them, weighing about a pound. That's about $60 million worth, he said.

Finding the emeralds isn't easy, Fisher said at the press conference. There are electronic devices to sniff out gold and silver, but no one's come up with a machine to detect the gems. But he suggested, in sort of a rough-cut way, that women divers seem to have a knack for finding the jewels.

Seemingly everything Fisher touches these days turns to gold. Or at least to silver. Even a ton of dirt that was scraped off parts of the treasure in the cleaning process assayed out to 60 percent silver, said Fisher, displaying a thimble-sized silver ingot risen from the residue.

These days Fisher is all smiles and has a glad hand for everyone. And it isn't easy for him to recall that his 16-year quest cost him one of his four children.

"Yeah," he said, recalling his son Dirk's drowning. "It makes you wonder if it's worth it . . . But he was so fanatic in going after the treasure, I knew he would have wanted us to continue."