GRAND BAHAMA ISLAND -- This column is about swimming with dolphins and wrestling a blue shark and snorkeling way too far from the boat (I think we did that several times), and a few other energetic things, too.

You see, George Plimpton and his family have been staying with me for the past week, and I have needed every drop of energy that clean and godly living provides simply to keep up.

George, of course, is the man who participates in activities and then writes about them. There isn't a sport or skill he hasn't tackled, including hockey, judging an oyster-shucking contest, and (very soon) singing with a professional opera company.

"My role isn't quite the leading role in the opera," George says. "In answer to a question, I sing a very loud 'NO!' But I do hold the note for some time."

Well, as you can imagine, trying to entertain a person like George creatively is like trying to find that gift for the man who has everything. I did not want his trip to be the equivalent, figuratively speaking, of an extra-wide pink polka-dot tie. And when you realize that George's family is equally experienced in the exotic, one's brain begins to work in overtime.

I was therefore very thankful for the dolphins. You may remember some months ago I told you about my trip to Mexico to participate in the capture of six Atlantic bottlenose dolphins. We caught them in the Bay of Campeche, and flew them to Grand Bahama aboard a chartered airplane equipped with doctors and a special misting system.

The dolphins are part of a project sponsored by The Underwater Explorers Society and Open Ocean Adventures. Rather than being trained to do tricks, they are being trained to interact with humans on dolphin terms. By next spring, all six should be roaming the ocean during the day, scuba diving with us, interacting with swimmers on the beach, then returning to their enclosure at night.

Though the dolphins aren't roaming free yet, they are having a lot of fun in their enclosure with a very limited number of humans. Mike and Jeannie Schultz, trainers and originators of the project, put no more than five people in the water with them four times a day, and then it's up to the dolphins to make friends if they want to. And they certainly made friends with the Plimptons.

Taylor was the first one in the water. Taylor was 11 this month, beats most adults at tennis, and has the blond, freckled-faced good looks of a young TV actor. Last year, before he even knew about our dolphin project, Taylor wrote his school term paper on dolphins. He made an A.

But he had never touched one. He slipped quietly into the water, excited and perhaps a little nervous at first. All six dolphins were much bigger than he, and Taylor knew from his studies how powerful these creatures were. For an instant the water was still around him.

And then, as if on cue, Uno, the biggest dolphin, popped his head from the water about an inch from a very wide-eyed Taylor. Taylor tentatively touched Uno's snout, then rubbed his soft and pink neck, and then Uno decided to take Taylor for a ride. Uno pulled him the length of the 30- by 90-foot enclosure -- and I don't think a young boy can muster a bigger grin.

Medora was in the water next. Medora learned to scuba dive here with me several years ago, and I have seen her grow into a dramatic young woman, as decent as she is pretty. Medora is quiet, tentative in new situations. But she had no time to be tentative here. Stripe introduced himself by surfacing just long enough to shoot a stream of water in her face, and then Kayla and Stripe both circled Medora for an instant before simply floating in front of her, waiting patiently for back and stomach rubs.

George and his wife, Freddy, went in last. Tanned, blond, and as graceful as the movements of the dolphins themselves, Freddy went to the dolphins without hesitation, literally with open arms. I can only describe her expression at first contact as that you would have on holding a long-lost child.

George, the lankiest member of the family, floated in and out of all this activity, touching each dolphin, at times gently holding on to his kids or Freddy as they touched the dolphins.

I realize I'm telling you more about the people's reactions than the dolphins', but that is the nature of this experience. These mammals bring out a lot of unspoken feelings in both participants and observers, and though I don't plan to enter the debate right now about their true intelligence, I keep thinking dolphins remind me an awful lot of a very bright person whose language I can't understand.

The dolphin experience was part of every day with the Plimptons, and it was usually the beginning of our water activities. We snorkeled so much over the island's shallow reefs most fish got to know us by name. Snorkeling and free-diving are skilled sports, though you may not think so. Learning how to clear your snorkel without choking and simply learning how to go under the water gracefully takes practice.

But after a few hours, the gang looked like pros. For a graduation snorkel, we towed a float out about 500 feet from Silver Point jetty and free-dove into a blue hole about 10 feet under the surface. This particular blue hole connects to the island's inland cave system, and many large fish hide in its darkness.

Taylor and I dove down holding hands, as much for courage as for safety, and held onto the hole's edge long enough to watch large, irridescent Queen Angel Fish swim by. Blue holes blow and suck with the tides, and this particular hole was beginning to suck in as we held onto the ledge. The suction gently tugged at us and for a moment scared me. I decided not to swim too close to the hole any more, but Taylor wanted to swim in even deeper. I won that debate.

Blue holes and dolphins aside, our most unusual adventure of the week was the shark wrestle. As a matter of fact, I think we are the only people in the world to actually witness the SINKING of a shark.

Since "Jaws," there's probably not a living soul that doesn't worry about encountering a shark while in the ocean. Scuba divers have that worry as much as anyone, but we all brag about shark sightings to appear cool. "Oh yeah, I saw a 20-footer this morning," we are apt to say calmly, conveniently omitting any mention of the absolute terror we may have felt.

Since shark sightings are about as common as snow down here, the Explorer's Society several months ago decided to create a good underwater site gag: anchor a couple of very lifelike plastic sharks on a reef and let divers snap photos with the beasts.

The idea was great, but the execution has been (and probably will continue to be) a little flawed. John Englander, the president of the society, happily had two enormous sharks designed, flew them here on his plane, and, two months ago, headed out to sink the first one, a blue.

The shark had other ideas, however. Because of some minor design flaws, it first refused to sink, and then sank too quickly, thereby "imploding" at about 30 feet. An imploded shark doesn't look at all menacing, so it was removed for redesign and repair.

The repaired shark returned to the island during the Plimptons' visit, and we eagerly joined the small flotilla of spectator boats heading to sea for the second sinking. Shark jokes were shouted from boat to boat with the regularity of our boat's engine.

We anchored 500 feet from the shark vessel and began to snorkel over. The shark, frozen in an "attack" stance with its teeth bared and its back arched, was being lowered, tail first, in the water as we approached. The creature instantly popped out of the water like a cork, as if the seas were too cold for it. This duel continued for 20 minutes, when finally eight divers were able to subdue it and actually make it to the reef 40 feet below.

For a minute, there were a lots of thumbs-up signs under the sea as the shark floated nobly above the reef, fastened with thin wires, small bubbles of air escaping from its sharp-toothed mouth as its cavities continued to fill with water. Unfortunately too much water. The shark grew top-heavy, and the tail began to drift upward like a slowly rising drawbridge, sticking finally in the upright position. Sharks are menancing. Even plastic sharks are menacing. But a plastic shark doing a nose stand is not. Within an hour the creature was back aboard the boat and the flotilla returned to shore, a subdued lot indeed. We took the shark to the Tide's Inn and had a beer with it. Well, as if all this activity were not enough, that night we went disco dancing -- for the second time. If I survive the rest of the Plimptons' visit, I'll see you in two weeks.