Vieques, the tiny Puerto Rican island, is so sleepy that its guard dogs often doze off in the streets. Writer Susan Choi explores its gorgeous beaches and has one of the best meals of her life.

"Hay perro bravo," warned the small, weathered, hand-painted sign on one of Vieques's main roads. Behind the sign lay the perro himself, a vision of the sort of complete relaxation only dogs can achieve, laid out flat on one side with all four legs stuck out, as if he'd been steamrollered by slumber. The perro bravo is a good emblem for Vieques, the tiny Puerto Rican island: just well known enough to need a guard dog, not so well known it needs the dog to wake up.

Four miles wide and 21 miles long, Vieques remains one of the least developed destinations in the Caribbean. Traffic is still a matter of two Viequenses, driving in opposite directions, stopping in the road for a long conversation. There are still more cows, goats and chickens on the street than taxis. Indeed, much of Vieques feels untouched—its plush forest largely uncut by roads, its white crescent beaches uncluttered by picnic tables—and this is ironic, because the island has been tightly held until just recently.

For over half a century, Vieques was used by the United States Navy as, among other things, a bombing range. But in May of 2003, the Navy withdrew, after years of protests about the military presence. I had followed the controversy myself, with only a modicum of interest. That poor little island, I'd thought, envisioning a wasteland of bomb craters. What never crossed my mind was that the Navy's stewardship had shielded Vieques from commercial development. The opening of a 156-room chain hotel, the Wyndham Martineau Bay Resort, signals the start of a new era.

Of course, this long reprieve from development also means that today the island is a tourist attraction with few tourist amenities. Before the toy plane taking us from San Juan to Vieques even landed, my husband and I were forced to talk to a couple whose specialty seemed to be going to Vieques and then complaining about all the ways in which it isn't, say, Mustique. Of course it isn't: If Mustique is what you want, Mustique is where you should go. Vieques offers something different. The island is very much itself—precisely what we'd hoped it would be.

Given such high hopes, we'd taken care to lower other expectations, mostly regarding the food. Imagine our surprise, then, when we turned up a place called Chez Shack. It's on one of the narrow, densely forested roads that link Vieques's Atlantic and Caribbean coasts, where hairpin turns might suddenly reveal a vista of perfect blue ocean or, just as often, a wild horse having lunch. Chez Shack, pressed as close to the road as the horses are, looks more like a backwoods honky-tonk than the unlikely site of one of our favorite meals not just on Vieques but anywhere: baked crab with a habanero kick; the creamiest, garlickiest tostones (fried plantains) of our lives; a succulent pork chop with pickled tomatoes; and a dizzying dessert involving pineapple nectar, spiced rum and jalapeños. All had been cooked by a bandanna-clad guy in an open-air space the size of a phone booth. Could this get any better? It could: The meal ended with an imported-cheese plate. Imported? But how? And by whom?

By Michael Glatz, it turns out, the man who seems to have singlehandedly revolutionized mealtime on Vieques. This is a man who orders everything from Alsace wine to couscous (all previously impossible to get here) through a connection in Boston. A man who personally arranges to have his order flown in to San Juan every week. And a man who, on the Big Day, rises at 3 a.m. to board an ancient cargo ferry bound for Fajardo, on the Puerto Rican mainland, then speeds to San Juan, loads his truck at the airport, races around the city picking up liquor and other provisions, speeds back to Fajardo, and gets on the ferry—hopefully—before it departs on a journey that, depending on the seas, often makes people wish they'd missed the boat and taken the toy plane.

"It's sort of like The Amazing Race," Chef Michael admits. (He is known only as Chef Michael, in much the way that the listings in the phone directory under "Taxis" read "Fernando," "Henry," "Ismael.") Chez Shack buys from Chef Michael, as can you, at his 10-month-old shop called FoodSpace. FoodSpace marks a turning point for Vieques, as does ¡Bravo!, the immaculate little boutique hotel in which FoodSpace is housed. They are both good reasons to stay in Isabel Segunda, the larger of Vieques's two main towns, on the Atlantic coast. The best pastries and arguably the best sandwiches on the island can be had at FoodSpace, enough to fuel a long day at the beach.

And though FoodSpace doesn't serve dinner, the nearby Café Media Luna more than compensates, with Asian-influenced dishes like phyllo-wrapped spicy lamb samosas, or lime-rubbed ahi tuna with avocado-lime ice cream. Tables are set snugly in tiny Juliet balconies from which you can gaze down on Isabel Segunda's nightlife—which, when we were there, was another perro bravo dozing off in the street.

Esperanza, Vieques's other main town, is a more comfortable tourist base camp, where locals and travelers lounge, eat, drink and promenade in the evenings. On the whole I found myself happier here, where the pounding Atlantic is replaced by the lapping Caribbean. A few minutes outside of Esperanza is one of the island's loveliest places to stay, the plantation-style Inn on the Blue Horizon. The hotel, on a bluff overlooking the Caribbean, houses the excellent restaurant where Chef Michael got his start.

The more we explored this tiny island—and its diminutive size is a characteristic that only visitors, not inhabitants, stress—the more I thought of dollhouses, Advent calendars and other miniature and secretive delights. One local told us that the best spots for snorkeling were "anywhere," and this turned out to be pretty true. But on Blue Beach—one of the "new" beaches, formerly Navy, now part of the recently established Vieques National Wildlife Refuge—I was too entranced by the clarity of the water around my ankles to even bother swimming out. Instead I sat down in less than six inches of sea and let a little purple-and-yellow-striped fish nose fearlessly around my toes.

The most mysterious waters in Vieques are no secret; they are cherished by locals, and eagerly shared. One evening we boarded a school bus in the company of a few dozen other courageous explorers and rattled off toward the discouragingly named Mosquito Bay. Captain Mark, our leader, stood in the front of the bus regaling us with stories as we lurched through sinkholes in the swamp of a road; at one point his flashlight fell out the open door and we ran over it (we continued, undaunted). A boat was waiting; we filed on.

Mosquito Bay, it turns out, is misnamed—it has no mosquitoes. But there are comets and meteors. It is a bioluminescent bay, which means that it is home to a rare plankton that glows a cool, eerie blue when disturbed. As our boat startled the fish, the fish startled the plankton—which left bright trails of light in the water. A boatload of people, travelers all, who had no doubt seen plenty of worldly wonders, gasped and cried out like children. Captain Mark stopped the boat, and one by one we dove off, waving our arms and legs as we hit the water to contribute to the dazzling display. It was another of Vieques's small miracles—all we had to do was jump in.

Novelist Susan Choi is the author of The Foreign Student and American Woman, a finalist for a 2004 Pulitzer Prize.