Perhaps history will say that the moribund sweet science - boxing - made its last stand here on the flight deck of an aircraft carrier off Pensacola, Fla.

Surely the orgy of bunkum here this week, culminateing Sunday in an old-fashioned pier fight on a 900-foot barge, is either the Alamo of the fight game or the beginning of the rebirth of the sport.

That, at any rate, is the wildly colored mural that Don King has painted as a backdrop for his U.S. Boxing Tournament of Champions that starts here Sunday.

His six-month extravaganza of elimination bouts - culminating in "U.S. Champions" in six pro weight classes - will be nothing less than "a historic moment, the renaissance of boxing." Or else King will fail or "create popular new champions" and "recapture the public's eye," in which case he will conclude that boxing "really is dead except for Muhammad Ali."

Only King, the man who wear his colorful but checkered past on the sleeve of his checkered suits, would dream of a big money, nationally televised tournament for a bunch of fighters that even he admits are nobodies.

Sunday's opening quarterfinals are the first of three fights for each boxer in the six different weight classes. For once for the boxers there is a pot of gold to go with the rainbow.

The heavyweight winner will make $180,000 for three fights, the runner Prater (11th in U.S.) in the heavyweight feature bout, the only one ABC will show in its entirety on its one-hour segment (4:30, WMAL-TV 7, on Wide World of Sports, is notorious for fighting only well enough to win while keeping his opponents at jab's length.

But as middleweight Collbert says, "the money the TV, fighting on this carrier has really got us steamed up. Guys have been waiting for this for years. Some of these fighters may transform overnight."

And so they are off to seek their fortunes on the deck of a carrier.

Bobby Cassidy might speak for them all. He, in a sense, is the man this tournament was created for.

At 32, the lefthanded lightheavy-weight has "never had a shot at the title. I been chasin' it for years."

The chase has been hard. From fighting on the streets in Queens as a youngster, Cassidy turned pro without an amateur-fight, with "no ambitions really."

"I felt good different times," says Cassidy, fiercely handsome despite the often broken nose, the bulbous scarred eyebrows and the reworked teeth that bespeak a 52-15-3 record. "But something always happened."

The "somethings" swim back to memory piecemeal - the four bad managers, the time" Pete Torro stopped me in the Garden when I never shoulda been in with him . . . too young," the time a blood disorder (toxic plasmosis) made him run out of gas in the last round of the one fight that might have brought a title shot.

Gradually, Cassidy became "you know an opponent. A white lefty who can punch can always get a fight."

Twice he "packed it in an retired." Other times "I just came up so empty inside it was ridiculous. Like there was no more of me left."

Cassidy went through a divorce and a brush with "far too much drinking," Slowly things are turning in the ring and King's tournament is "a break just when I needed it."

To stay out of bars. Cassidy became a movie buff, then a bit-part actor. He was even a spear carrier in "Rocky." "It was a little like they were filming my life," he says. "I loved that picture."

Pushing irony to the limtis. Bert Young, the actor who is up for an Academy Award as Rocky's handler in the movie is also one of Cassidy's old friends. Young will work in Cassidy's corner Sunday here against Willie Taylor. The analogy between Cassidy's life and the movie is so perfect that Cassidy would rather not discuss it to much.

"It's too much like a hype," he says. Thinking about Taylor is enough work for now.

"They say he's a beast. Nobody's ever had him off his feet," says Cassidy, lounging in jeans, sneakers and Navy pea jacket. "That's his rep anyway. But I like a guy to come to me. That's my style."

But he may not like Taylor coming at him.

"I'd rather see Cassidy up against a water buffalo," says Cassidy's manager. Paddy Flood.

Taylor is a charmer. Just ask him, up $90,000. The purses scale down to half that for the featherweights.

Anyone who ever cried for Marlon Brando in "On the Waterfront," or John Garfield in "Body and Soul" or Sylvester Stallone in "Rocky" has to feel something for the dozen gents who are fighting here Sunday. We know their lines by heart.

These fighters are the neglected, the short-changed, the underpaid and the cheated. They are the good guys with no connections, no luck, and, of course, no breaks.

They are the fighters that Ring Magazine (King's ticket to matchmaking respectability) says are America's best, but most of them are also a cast that tournament referee Jay Edson says "haven't taken more than $750 out of many fights."

King's hand-picked Dirty Dozen includes one paunchy heavyweight, a 32-year-old lightheavy with 15 defeats, a garbageman, a bartender, a roofer named "The Fighting Leprechaun." a guy who has never fought outside New JerseY, and a health food freak who carries a blender everywhere to make himself "a glass of lamp chops."

King is counting on the public falling in love with these guys as the tournament progresses. ABC-TV which bought the rights to the whole she bang for $15 million is counting on it, too.

There is talent here. Unbeaten Mike (King Cobra) Colbert, the almost unknown No. 1 middleweight contender in the world, should earn a title shot against Carlos Monzon. H. as expected, he takes out Jackie Smith Sunday and two more of that ilkthereafter.

Colbert wants exposure. But for most of the others it is a chance to become a contender, the way Terry never did in "On the Wateriront." Or to get a couple of genuine paydays. Or perhaps, like "Rocky," simply to prove to themselves that "I'm not just another bum off the block."

Most of the fighters in the tournament, even the best ones like heavyweight Larry Holmes (22-0), lack something. Holmes, who meets Tom "I'm a crowd pleaser," says the Joe Frauier style fighter, with the barest of smiles. "They never forget me. "I'm alway's the people's favorite. I get on my man and never get off." Taylor illustrates how he keeps his forehead inches from his victim's breastbone.

Taylor talks about his left hook - which recently knocked one Willie Mack unconscious for seven minutes - like Robert Frost disecting a sonnet: Mack's "white eyes rolling back, the "mouthpiece in the air" and the "legs still planted but the head already out cold."

It is that sort of "murder and blood" that middleweight Colbert calls "the key if this is going to catch on with TV. I'm a scientific fighter, but I know what the people want. Same as always."

The matches will have a hard time matching the theatrical impact of the promotion and the USS Lexington. The 42,000-ton carrier, now a training vessel for pilots, will try to steal the show in the crisp clear weather that is predicted.

The old gray carrier, built in 1943 after her namesake was sunk in the Battle of the Coral Sea, should be a glistening sight with 3,000 Navy men in uniform in the crowd.

To pump the fights. King has even brought unswerving Irving Rudd, master press agent, to work his magic, Rudd, who curses the current breed of "PR councilors and communications specialists who drink drinks with funny names," is not afraid to be a genuine press agent.

"You've got to think the unthinkable, like a fight on an aircraft carrier," says Rudd, whose research has unequivocally proven that King's event "is the biggest thing to hit Pensacola since they threw Geronimo in jail here."

Rudd, like the rest of a legion of oldster here, dreams that the fight game will come back the way it was. "The old gyms are all torn down," said Rudd. "I cringe every time I see a supermarket. Where are the names liek Kid Chocolate. Tin Can Rominelli, Bearcat Wright. All that's left is Ali and few vapid Irish fighters.

"Maybe this'll turn things around. Jezz, a whole generation don't know what it missed. People don't want to reminisce about tomorrow night's fight no more."

"What do you think?" said Rudd, turning to Cassidy, the light heavy with on last chance.

"I think," said Cassidy, "that things can only get better."