For three days, the boat filled with anxious fishermen dragged plastic baits over the heaving surface of a deep and apparently empty sea. Suddenly, with less than an hour remaining until the tournament's quitting time, the water exploded with white marlin.

"They were all over our boat," said Pete Fisher, the captain of a team of Florida fishermen who caught two white marlin, lost a third and then turned the boat toward Ocean City while some of the premier gamefish of the Atlantic still were performing aerial maneuvers in their wake. "I sat in the back of the boat crying because the fish were still there, waving their bills at me."

Fisher was one of 49 anglers on 13 teams competing for more than $72,000 in prize money this weekend in a tournament that was unusual for a few good reasons beyond the healthy payoff to the winners.

Unlike most saltwater tournaments that feature a display of dead fish at the end of each day's angling, the fishermen in this contest, sponsored by the newly formed International Billfish League (IBL), were awarded points only after tagging and releasing their catches.

"We're trying to set a new tone in the fishing world," said William McMurray, 48, the mastermind of the IBL, which consists of seven tournaments from Walker's Cay in the Bahamas to Texas, Florida, North Carolina and Maryland. "The catch-and-release concept has been a big hit, especially with the fishermen. They get such psychic rewards from letting the fish go."

McMurray and his backers are hoping their circuit will do for sport fishing what the PGA Tour did for golf: change it from a sport for the rich to a sport that can make you rich. After four tournaments, the IBL has awarded more than $400,000 in prize money. And if the venture is as successful as promised, first-place finishes might be worth as much as $250,000.

"You need a profit motive to make this work," said McMurray, a former president of U-Haul International. "We have tournaments where guys with $500,000 and $600,000 boats are competing for $1,000 in prize money. It doesn't make sense."

Even with the $8,000 fee required of each boat in tournaments, the IBL is losing money this year. Instead of the 100-boat fields they hoped to attract, contests have averaged closer to 20. But organizers in Ocean City this weekend said they expected to lose money the first year. Next year, they expect a stampede by contestants and commercial sponsors to join the tour.

"It does have great potential for fishermen to chase a lot of money," said Doug Parran, captain of a Maryland team that was in third place after the Ocean City tournament. Parran, a real estate banker in Lusby, Md., figures he and others on his six-man Bear team spend a few thousand dollars at each tournament. So far, they have won $20,542 in prize money. "We're not a group of millionaires, just working people," said Parran. "It costs us money to do this."

The Bear team caught two white marlin in the weekend tournament for a total of 130 points. Each tagged and released blue marlin is worth 400 points, white marlin 65 points and sailfish 50. If a contestant catches a fish that appears to weigh more than the point value, the fish can be killed and brought to the dock to be weighed. Every pound over the minimum is worth an extra point. For example, a 450-pound blue marlin is worth 450 points.

However, if a fish is killed that weighs less than its point value, you get zilch. In the IBL's first tournament, a Florida team lost $30,000 in prize money because it brought back a blue marlin that weighed 33 pounds under the 400-pound limit.

"That was a public relations man's dream," said John Good, the public relations man for the IBL.

Of 14 billfish caught during this weekend's tournament, only one was killed and brought back to be weighed. There was little question that the blue marlin caught by Randy Ringhaver of Florida was over the minimum.

"The first time it came out of the water, it looked like the Man himself was coming up to visit you," said Bill King, captain of The Bree, a 50-foot fishing boat worth more than $1 million. The marlin weighed 729 pounds, which easily took first prize of $29,717.

To guarantee that contestants do not lose track of how many fish are caught and released, each boat must carry an observer from a competing team. To prevent an observer from taking a payoff, the top two finishers in each tournament must submit to lie-detector tests.

"This is the best concept ever arranged for a fishing tournament," said Parran. "I like the catch-and-release aspect and I feel very comfortable that all the possibilities of cheating have been removed."