Caribbean vacations gone wild

When it comes to a Caribbean vacation, the idea of an extreme activity takes on new meaning. Would it be a walk on the beach? Possibly. Eating lunch delivered poolside? Closer. A marathon towel-napping session? Definitely.

But beyond the sunning and swimming and the usual surfside water sports, the Caribbean islands offer a wealth of activities that will test your strength, stamina and stomach. From the deepest depths to the darkest caves, these expeditions will bring you face to face with creatures that lurk on the ocean floor and glow in the night.

Most of these adventures are not for kids, and it's best to be fairly physically fit. But if you're brave enough, you may just find yourself pushing your limits, in the Caribbean, of all places.

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The biggest highlight of snorkeling is usually swimming among schools of fish, or seeing manta rays from afar. But several outfitters on Turks and Caicos and the Dominican Republic offer visitors the chance to frolic with a much larger marine animal.From January to March, humpback whales mate and calve in the Silver Bank, a region in the Atlantic midway between Turks and Caicos and the Dominican Republic, before migrating to colder waters. Whale watchers can slip into the water there and snorkel with the 10- to 12-foot calves as their mothers watch from 40 feet below, says Wayne Hasson, president of Aggressor Fleet.

"The baby will dive down and come back up to the surface," he says. "It's one of those things you have to put on your bucket list."

The Aggressor Fleet offers weeklong expeditions (www.aggressor.com; $2,795 a person, including meals and accommodations), departing from Puerto Plata, Dominican Republic. Participants leave the main boat on inflatable rafts, led by guides, to get close to the whales. There are a few situations in which snorkeling is not possible, like when two males are fighting for territory or a few males are trying to impress a female whale. But the calves are very curious and nonaggressive, and participants are taught to approach those using slow, gentle movements.

Most people come in March, when the whole pack moves a little more slowly, says Dale Barker, an owner of Oasis Divers Grand Turk, which

offers a three-hour whale-watching tour (http://oasisdivers.com, $65 a person). Snorkelers can swim with the whales on about 40 percent of the trips.

"Being in the water and seeing a whale is a life-changing experience - you'll never forget it," Barker says.

"They're majestic, huge creatures, but they're so graceful in the water. With one tiny flick of a tail they're gone in a second."

* * * * *It is one thing to fly high above the beach, feet dangling in the air, with just a harness to keep you from plummeting to the sea. It takes a different kind of traveler to do it sans swimsuit. Naturists seeking such a thrill can strip down on Orient Bay in St. Martin, one of the Caribbean's most famous clothing-optional beaches.Club Orient (http://cluborient.com), the only nudist beach resort on St. Martin, does not offer nude parasailing (though it does offer nude snorkeling and clothing-optional day cruises), but some independent outfitters like Sun Smile Parasail (http://sunsmileparasail.com, $60 a person) welcome naked visitors aboard their sky-high adventure.

* * * * *At 1,009 feet, Mount Tamana is the highest point in Trinidad's Central Range. After a steep, 30-minute climb to the summit, hikers are rewarded with more than just stunning views of the island's northern and southern ranges. They also will encounter the first chamber of Tamana's intricate cave system, which provides an intimate look at the thousands of bats residing within.

"When you look at the faces of the people on the tour, they're usually a mix of excitement and fear," says Courtenay Rooks, owner of Paria Springs, an eco-adventure tour company. "Adventure is about pushing yourself farther than you ever have before, mentally or physically."

More adventurous travelers can explore farther into the second chamber of the caves, where the bats can have a wingspan of about one foot. More than 500,000 bats live in the chambers, and unlike other areas of the world, where large quantities of one species are found in one spot, in Tamana Cave more than 12 species have been identified. The full-day expedition (http://pariasprings.com; $85 a person) includes transportation, snacks and drinks.

At sunset, the group returns to the entrance of the caves to watch as a steady stream of bats flies within centimeters of visitors' faces.

"You can literally feel the wind as the bats fly by," Rooks says.

* * * * *On a moonless night, slicing a kayak paddle through the water of Puerto Rico's bioluminescent bays turns the endless black into a flurry of glowing lights. Two bays and one lagoon - La Parguera, between Mayaguez and Ponce; Puerto Mosquito in Vieques; and Laguna Grande in the Cabezas Nature Reserve in Fajardo - are full of single-celled bioluminescent dinoflagellates, half-plant, half-animal organisms that emit a flash of light when agitated.The high concentration of these creatures can provide enough light to read by, says Irca Gonzalez of the Puerto Rico Tourism Co. Waldorf Astoria's El Conquistador Resort, in Fajardo, arranges kayaking excursions for guests (www.elconresort.com; $88.24 a person). And if you're not a kayaker? You can swim in Puerto Mosquito in Vieques, which was named one of the 50 most romantic places on earth by Travel & Leisure magazine.

* * * * *Dominica, a tropical rain forest island, has seven active volcanoes, mountains with elevations of nearly 5,000 feet and more than 300 sources of water, including Boiling Lake, billed as the second-largest hot spring in the world. Over the years, the water has carved hundred of canyons into the rock, some reaching 200 feet long, that Richard Metawi, the owner of Extreme Dominica, calls "almost cathedral-looking." And the only way to get inside is to go canyoning: a combination of hiking through the island's verdant forest, rappelling down waterfall walls and plunging into canyons filled with crystal clear water, all while wearing a wet suit, helmet and harness.

"Ninety percent of the fun is jumping from pool to pool," Metawi says. "And you never know what's around the other corner."

Extreme Dominica's canyoning tour (http://extremedominica.com; $150 a person) takes three to four hours. Though there is no official certification, all participants receive training before the expedition begins. Previous canyoning experience is needed for a more advanced trip, like one that includes an overnight stay and a 270-foot waterfall.