Vieques, Puerto Rico — Swimming in the warm, bioluminescent waters of Mosquito Bay, I have more "stars" at my fingertips than there are in the inky sky overhead. Tiny, twinkling specks trickle from my palms as I lift them out of the water. They cling to my clothes like living sparks, gleaming for a moment before fading away.

Under the surface, my arms and legs create a green wake as I paddle, making me feel like a human glowworm or a firefly looking for some action, thanks to the presence of billions of microscopic organisms known as Pyrodinium bahamense, which light up when disturbed.

Scott Warnke/Special (ENLARGE)
A shady gazebo on the Malecon overlooks the striated blue waters of the Caribbean.
MOST POPULAR STORIES Power still out for many in wake of tornadoes Morehouse valedictorian stands out -- he's white Ryan the right QB for Falcons | Mark Bradley Gallery | Bushes share joy about Jenna's wedding | ajc.com Three Conyers high school students killed in wreck
EMAIL THIS PRINT THIS MOST POPULAR
IF YOU GO Getting there • Fly into San Juan International Airport. From there, you can fly to Vieques or you can take a ferry or fly from Fajardo to Vieques. For flight information: http://www.vieques-island.com/geninfo.shtml. For ferry information: 787-741-0800. Where to stay • Martineau Bay Resort & Spa features 138 spacious guest rooms and suites, two Atlantic Coast beaches, tennis courts, a spa and a pool with a swim-up bar. In fall 2006, the gated resort is slated to become a W Hotel. Rates: $309-$899 per night, but check for specials under $200. 787-741-4100, http://www.martineaubayresort.com. • The Inn on the Blue Horizon, about one mile west of Esperanza, offers casually elegant accommodations atop a bluff overlooking the Caribbean. One-story duplexes, some with ocean views, encompass a total of 10 rooms. $110-$370. 787-741-3318, http://www.innonthebluehorizon.com • Hector's by the Sea, just west of the Inn on the Blue Horizon, features modest guest cottages tucked around a pool and Jacuzzi with views of the Caribbean. Each of the three accommodations features its own hammock, kitchenette and en-suite bathroom. $85-$165. 787-741-1178. e-mail: hmbtc@hotmail.com. Where to eat In addition to the watering holes along the Malecon: • Island Steakhouse on Route 201. This romantic restaurant, tucked in a tree house among papaya, mango and coconut trees, features a cocktail party from 5 to 7 p.m. Tuesdays and a delicately spiced Moroccan steak on Novo Latino night. 787-741-0011. • La Dulce Esperanza offers one of the best breakfast or lunch deals around, with ham and cheese sandwiches on fresh-baked bread for $2.50. Large pizza $15. 787-741-0085. • Mamasonga is a tiny breakfast joint in Isabel Segunda that serves heaping portions of french toast, pancakes and omelets. 787-741-0103. • Al's Mar Azul, across the street from Mamasonga, sports a pool table, dart boards and tables right on the water. It's a favorite among local bartenders and wait staff. Drinks only. 787-741-3400. Getting around • A four-wheel drive rental vehicle is recommended. For a listing of rental agencies: http://www.vieques-island.com/geninfo.shtml#car. Touring the bio-bay • Island Adventures uses an electric boat to ferry guests onto Mosquito Bay, where they can swim in the bioluminescent waters. $30 adults, $15 children 4-12, free ages 3 and younger. 787-741-0720, http://www.biobay.com. • Blue Caribe Kayaks takes guests on a guided kayak tour of Mosquito Bay. It's an intimate way to experience the bay, trailing your hands through the water or slipping over the side for a swim. $30 per person. 787-741-2522. Information • Puerto Rico Tourism Co., 1-800-866-7827, http://www.gotopuertorico.com. Also, these sites are useful: http://www.vieques-island.com, http://www.enchanted-isle.com and http://www.viequestourism.com.

"Now this was worth the price of admission," says Paul Leveillee, a Massachusetts mortgage broker honeymooning with his wife, Wendy, as he fans his limbs to make a ghostly angel.

It's an otherworldly encounter — and Vieques, a narrow, 21-mile-long island off the coast of Puerto Rico, is one of the few places in the world where you can experience this. Not surprisingly, the bio-bay is the top attraction on an island that almost no one has ever heard of — unless, of course, you count the appeal of visiting one of the last relatively undeveloped outposts of the Caribbean. (Vieques, which derives its name from the Taino Indian word for small island "bieques," is pronounced vee-AY-kes.)

The U.S. Navy, which used Vieques as a bombing range for decades, is largely responsible for the island's low profile. The armed forces moved in during World War II, erecting tall chain-link fences topped with razor wire that rendered two-thirds of the island off-limits. Though the Navy only shelled a small portion of Vieques a couple of times a year, travel agents apparently didn't consider a live fire training facility a prime vacation destination. Only adventurous tourists discovered the island's sandy white beaches, lapped by clear aquamarine waters, and the laid-back lifestyle of the 9,000 or so primarily Spanish-speaking residents who occupied the remaining third of the island.

Then, in 2003, after decades of opposition from Puerto Ricans, the Navy withdrew. Now Vieques has become a buzzword among travelers looking for the next "undiscovered" frontier.

Most of the Navy's former holdings have been turned over to the U.S. Fish and Wildlife Service, meaning that the vast majority of the island will likely remain undeveloped. This translates to thousands of acres of undulating hills where horses roam free and miles of beaches with few buildings of any kind, save for the small picnic gazebos beneath the palms that fringe the shore.

Some areas remain fenced off, but most of the island can be explored, provided you have a four-wheel drive vehicle to negotiate the bumpy, unpaved roads that snake through the wilds and lead to several former Navy beaches. (Maybe the military figured that when trying to discourage interlopers, potholes the size of lunar craters are the next best thing to land mines.)

Those dotted lines on the map represent roads that only fans of Six Flags' rickety wooden Scream Machine could love. But those who brave them may well find they're the only souls on the beach, except for the occasional topless sunbather (illegal on public beaches, though not uncommon) or a fisherman swinging his fishing line overhead like a lasso as he wades into the surf.

There are only two towns on the island — Isabel Segunda, an Atlantic port, and Esperanza, on the Caribbean. Isabel Segunda is larger and more populous, with a maze of restaurants and shops sandwiched between modest cinderblock homes. The main tourist attraction here is the 150-year-old Fort Conde de Mirasol, a former Spanish fort that now serves as a museum.

A few miles west of Isabel Segunda is the island's only large hotel, the 138-room oceanfront Martineau Bay Resort & Spa — a former Wyndham property that is slated to become a W Hotel next fall.

Esperanza, by contrast, is a breezy little beach town with almost no commercial development beyond a half dozen open-air restaurants and bars strung out along the Malecon, an attractive boardwalk that serves as the heart of the community. On weekends, tourists and locals mingle over beers and burgers at Bananas (motto: "A Gin-U-Wine Sleazy Waterfront Dive"). They groove to tunes by Blondie and Michael Jackson at La Sirena, a seafood restaurant that doubles as a dance club when the DJ breaks out his discs. And they wait for the tables nearest the street at Bili's, a seafood and steak restaurant, in order to watch the action unfolding along the Malecon.

In the evening, young men and women canter spirited horses up and down the road, vying for space with the cars that slowly cruise by blaring Spanish music. A local family plays dominos on the boardwalk, and behind La Nasa, a tiny waterfront cantina, middle-aged couples sway to a symphony of salsa and surf.

During the day, families play in the waters just off Esperanza's municipal beach. As children jump off the pier, Randy Edwards, a bartender who moved here five years ago from Marietta, sits in a plastic chair outside La Nasa smoking a cigar.

"It's just another lazy Sunday afternoon," says Edwards, who serves his signature Caribbean Cosmopolitan (a combination of Bacardi Limon, white cranberry juice and Cointreau) at M Bar, a hip watering hole and restaurant across from Martineau Bay. "I'll have a cigar, a couple of beers, and go swimming in the afternoon."

Beyond these simple pleasures — swimming, snorkeling, fishing, hiking, horseback riding, mountain biking — there's not a whole lot to do on Vieques. According to your point of view, that's either a blessing or a bane.

"Vieques is not for everyone," admits Rebecca Wilmot, whose small bakery, La Dulce Esperanza, is in a neighborhood of tidy houses just uphill from the Malecon. "If you like casinos and shows ..." Wilmot's voice trails off and she shrugs, meaning, "sorry, you're out of luck." There's not even a movie theater.

But Vieques has come a long way since Wilmot's first visit in 1984, a few years after her father bought a bat-infested restaurant in Esperanza.

"The airport looked like a chicken coop," she recalls. "The Malecon wasn't built yet, and there was trash everywhere."

Twenty-one years later, that restaurant, TradeWinds, is one of Esperanza's most popular eateries, and property values have gone through the roof. "The year the Navy left, it was like the gold rush," recalls Wilmot, a former nurse from Boston who moved here four years ago. "Everybody was coming down and buying property."

Growth isn't necessarily a bad thing, according to Hector and Mary Matos, who run Hector's by the Sea, a collection of modest guest cottages overlooking the Caribbean near Esperanza. "Tourism is rising little by little, but there's not enough yet for tourists to do, like shopping and restaurants," says Hector, a native of Puerto Rico who grew up on Long Island, N.Y. "And you don't have enough rooms. I think a couple more hotels would be just fine."

Mary, who lives with Hector and a bilingual parrot named Frankie in a one-room cottage tucked among the guest houses, nods in agreement. "We have to have progress, but it has to be controlled," she says. "It has to be responsible, with good planning and people who care."

Delicately poised as it is between backwater anonymity and burgeoning recognition, it's not surprising that Vieques has become something of a celebrity retreat. Jennifer Lopez and her husband, Marc Anthony, are rumored to own land on the island. Uma Thurman and Will Smith (though not together) have reportedly vacationed here, and my husband and I saw Richard Gere at the Martineau Bay Resort & Spa, apparently on a break from a movie set on Puerto Rico.

Vieques is also proving a popular locale for honeymoons and destination weddings. Sherri Franks and Bennard Gillison Jr., former Atlantans who live in Spartanburg, S.C., recently celebrated their nuptials on an ocean bluff at the Martineau Bay Resort & Spa with 60 friends and family.

"I was intrigued by the fact that it was described as this hidden jewel of the Caribbean, how it was off the beaten path," explains Franks, an obstetrician-gynecologist. "I wanted to really get a chance to mix with the locals and just hang out.

"And Bennard thought the idea was cooler than cool. He said, 'Can I wear shorts? We can get married on the beach barefoot!' I was like, 'No! It's not that kind of wedding,' " says Franks, who wore a strapless white satin Reem Acra gown. The groom, displaying the sort of wisdom that bodes for a long and peaceful marriage, wore a classic tuxedo.

In addition to their wedding and reception, Franks and Gillison invited their guests on a tour of the bio-bay. Splashing in the glowing water, guide Mark Martin pointed out the constellations representing the couples' astrological signs, and as if on cue, a blazing star streaked across the sky. But ultimately, the heavens couldn't compete with the glittering universe of the bay.