No doubt about it, dolphins have a certain mystique. So it's not hard to fathom why during the past five years an estimated 10000 people have flocked to aquatic centers in Florida and Hawaii, paying as much as $65 for the chance to cavort for a few minutes with these winsome mammals. For Cheryl Popp, a 37-year-old newspaper executive, a 30-minute session at the Dolphins Plus tank in Key Largo, Fla., was the experience of a lifetime. "It was exotic, erotic, beyond Disney, better than sex!" she exclaimed. "Nothing can compare to the soothing feeling of being propelled around the water by a giant dolphin. It was awe-inspiring!" Jessica Grosso, 13, of Boca Raton found the experience a bit less metaphysical, but no less exhilarating. "The dolphin kissed me and then danced with me, and I pet it all over!" she squealed.

That same sense of wonder has motivated Ric O'Barry, a onetime trainer on the TV series Flipper, to devote 30 years of his life to working with dolphins. It has also led him and a growing number of other conservationists and animal-rights activists to demand that the swim parks be closed. They charge that the facilities frivolously abuse a highly intelligent mammal and point out that, typically, the dolphins are forced to perform with human visitors three times a day, seven days a week. As evidence of the potential for harm, critics cite the deaths this year of two dolphins at a swim center in Hawaii. "These programs don't work," says O'Barry, principal organizer of the Dolphin Project, which is dedicated to preserving the creatures in the wild. "Dolphins have been reduced to draft animals. The only way the public should see them is face-to-face in the ocean."

The chorus of outrage grew even louder last week when a killer whale at Sea World in San Diego bled to death after a collision with another whale. In their effort to shut down the dolphin swim parks, opponents have seized on the U. Marine Mammal Protection Act. Passed in 1972, the bill restricts the capture of dolphins and other marine mammals except in a few circumstances, including scientific and public display; a new amendment requires a display to have an educational or conservation purpose. (Federal law protecting the dolphins does not cover swimming with them.) Last fall, in response to complaints from environmentalists, U.S. officials imposed a moratorium on new licenses for swim parks, and announced that the four centers now in operation—three in Florida and one in Hawaii—might not have their permits renewed when they expire at the end of this year.

The swim center operators object, contending that their programs generate public awareness and sympathy for the dolphins, which may be the best hope for the mammals' survival. Every year, tens of thousands of dolphins are killed by commercial tuna fishermen in the Pacific. "When you get a person down on the docks and a dolphin looks them in the eye, that's when we give them a lecture on dolphin slaughter," says Dr. Rae Stone of Dolphin Quest, the swim program at the Hyatt Regency Waikoloa in Hawaii. Even some environmentalists are forced to agree. Denver Leamon, head of Greenpeace Hawaii, initially opposed Dolphin Quest, but now endorses the enterprise because it generates funds for research on dolphins in the wild. Some swim center operators also maintain that the programs can be therapeutic for handicapped or emotionally troubled people by providing them with a relaxed, playful environment which helps alleviate their inhibitions and anxieties.

O'Barry and others, however, insist that the centers' only real purpose is to make money for the people who run them. "Dolphins in captivity don't represent dolphins in our ecosystem. They're reduced to circus performers," says O'Barry. "If that is educational, then a boxing kangaroo is also educational. And so is a dancing bear chained to a tree." What's more, swimming with dolphins may pose certain risks. Male dolphins, in particular, are highly sexed, and, when in the mood, can be quite aggressive. Kathleen Forti, who visited Dolphins Plus last year, recalled being mauled by an amorous dolphin. "I thought I was under some kind of attack," she said. "I felt both battered and raped." Some operators concede that visitors have been bruised and raked by the dolphins' teeth.

The final decision on the fate of the swim programs is expected before the end of the year. Rick Borguss, owner of Dolphins Plus, says that he, for one, would welcome closer government regulation of the centers in the interest of keeping them open. He and other operators maintain that dolphins are not endangered in captivity, and experts now believe that the two dolphin deaths in Hawaii resulted from natural toxins in fish that could just as easily could have been picked up in the wild.

Such claims are unpersuasive to O'Barry, whose son, Lincoln, suggests that those who really want to know what it's like to swim with dolphins should do as he and his father did: sign on with one of the growing number of expeditions that take people out on the ocean where they can frolic with their sleek playmates in an unconfined setting. "The dolphins touched me, swam with me, communicated without speaking," says Lincoln, 17. "You can't compare this to swimming with them in a tank." With a price tag of more than $1,000 a week, the ocean junkets aren't for everybody. But the cost just might remind people that it can be cheaper and nearly as much fun to swim with other frisky mammals—each other.

—Bill Hewitt, Linda Marx in Key Largo