What's this? "Boston" Rob Mariano, reality TV's improvisational genius, suddenly needs a script? Standing on the beach in front of the Atlantis, Paradise Island resort in the Bahamas—where in less than a day, on April 16, he would marry his Survivor sweetheart Amber Brkich—Mariano is asked if he has memorized his wedding vows. "Are you kidding me?" he says. "No, I'm not remembering them. I have them on paper—on paper! Let's not go crazy here. We have a lot going on."

That they do, in the form of a wedding spectacular featuring 230 guests and a small army of producers and cameramen capturing it all for a two-hour special airing May 24. But first the beaming couple had to survive a rehearsal dinner, which like the wedding was orchestrated by planner-to-the-stars Colin Cowie. Working closely with Amber ("She has great taste and she knows what she likes," he says), Cowie converted the spacious Bridge Suite at the Atlantis into a beach-themed dining area for 40 relatives and friends. The fare: a four-course Italian meal—including penne pasta with garlic shrimp and a chocolate fountain with fresh fruits—that was micromanaged by Rob. "Amber's adventurous; she'll try anything," says Atlantis chef Mark Percival, who prepared the meal. "Rob is more specific in what he wants."

During dinner the couple unveiled wedding surprises to each other (Cowie's idea). Rob, 29, showed a tape of himself and his buddies helping decorate the couple's Pensacola, Fla., home, while Amber, 26, gave her beau a Boston Red Sox painting that she had had signed by the team. The real surprise may be just how genuinely in love they are, considering they courted on an island without running water, much less breath mints. "I've never seen so much chemistry between two people," Rob's brother Mike Mariano said at the rehearsal dinner. "Who would ever meet on TV on a reality show and realistically be so happy?"

In fact their time together on Survivor: All-Stars in 2003 helped them become as close as they are. "They had no TV, no newspapers, no nothing, and they probably had more serious conversations than most people who've been married for 10 years," says Chrissy DiCicco, one of the eight bridesmaids. "Rob said, 'I feel like we're just making it official, because to me, we've already been married for so long.'"

Even so, there must have been a few pre-wedding jitters at the rehearsal dinner, no? Actually, says Cowie, "Amber is not a stressed-out bride. She's no Bridezilla. She's so gracious." Nor did all the cameras and spotlights seem to bother Boston Rob, who near the end of the dinner leaned toward his bride-to-be and gave her a gentle kiss. No script needed there.

Alex Tresniowski; Cynthia Wang and Ulrica Wihlborg in the Bahamas