Behind the Scenes at Disney World

"When you're in the water," our guide, Amanda, instructs us as we line up on the metal grate at water's edge, "you will be part of the exhibit. People will take pictures of you. They will go nuts. You can wave, make hand gestures." She pauses.

"Just remember, there are some hand gestures we don't do at Disney."

The actual jump into the tank is just the climax of a two-hour prowl through one of the largest artificial marine environments in the world. The first hour takes us by manatee and dolphin tanks, into an ichthyological sickroom and past boxcar-size pumps that filter the water at the rate of 35,000 gallons a minute.

Halfway through, we take a break in a kind of diver's greenroom decorated like a seafood restaurant. We watch a video and get a briefing on the breathing equipment. Amanda assures us that the numerous sharks and rays and sea turtles will do no more than nudge us. "You'll be using the same platform as the feeders use, so they will definitely be interested when you get into the water."

She leads us to locker rooms, where we find fresh towels, hot showers and wet suits in our sizes waiting for us.

Up on the platform, we shoulder into the tanks and Amanda snaps our pictures just before we put on our masks. (After the swim, we'd find the printed pictures and a tour T-shirt waiting for us). A dive master runs through a few hand signals and warns us to stay away from the fence that separates the dolphins from the main tank (they can be aggressive if you get too close).

"In you go," he shouts, and I plunge headfirst into a sea turtle.

He's a massive old thing, twirling like a dancer as I right myself and get accustomed to the air regulator. We're nose to nose for a while. Soon we're joined by a spotted eagle ray, and then I'm engulfed by a shimmering school of jacks. The water is warm, salty and perfectly clear. The tank is huge, and I quickly lose sight of the other swimmers.

It's half an hour of such blisses with the fishes. There are 65 species of them. Below, the sharks cruise in restless circles. The spectacular coral towers -- absolutely fake -- rise in arching towers from the shell bottom. Behind the five-inch thick acrylic windows, I see shadowy forms, pointing and clicking . . . at me.

I wave and make Hidden Mickey shapes with my fingers, feeling oh-so-immersed in Disney's world.