CASTRIES, St. Lucia - I'm not even halfway up Gros Piton, the taller of St. Lucia's signature twin peaks, and I'm already starting to perspire from places where I didn't even know I had pores. My shins. My elbows. My earlobes.

It's an inauspicious start to what I've dubbed my "Surf and Turf" tour of St. Lucia, a lush isle in the West Indies' Lesser Antilles. Over the course of a week, I plan to scale the 2,619-foot summit of Gros Piton, scuba dive along the coral reefs, and ride horseback through the surf. But at this moment, my body is screaming, "Abort! Abort!"

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"Please tell me this is the steep part," I gasp, scrambling up yet another massive pile of rocks behind my guide, taciturn Chad William, lean and bearded. "If not, just lie to me, man," I implore him. "Keep hope alive."

Hailing from the tiny village of Fond Gens Libres, founded at the foot of the mountain by freed slaves more than 200 years ago, William hardly breaks a sweat as he negotiates the trail, which was carved centuries ago by villagers seeking high ground as the invading British threatened to capture and re-enslave them.

But it's not just the mountain's historical relevance that has brought me here today. It's the promise of unparalleled panoramas.

More than two hours into the hike, we reach the climax of our climb. Leaving the shade of the forest, we enter a clearing and are confronted by a stunning view of one symbol of St. Lucia - the 2,460-foot conical peak of Petit Piton - while standing atop the other, Gros Piton. Both thrust straight out of the turquoise Caribbean, book-ending a crescent of white beach. My legs are aching and I'm panting like an obscene phone caller, but for me, attaining this summit is as rewarding as climbing Mount Everest.

If the UNESCO World Heritage-listed Gros Piton whets your appetite for adventure, you can also sign up for ziplining, mountain biking, Segway tours, and guided hikes through the 19,000-square-mile Edmund Forest Reserve, home to 37 bird species, three types of snakes, and 1,665 plant species, including one whose root can be made into a very, er, stiff drink. "That's the St. Lucian equivalent of Viagra," a forestry officer explains with a sly smile.

Good to know, but for my next adventure, I'm most interested in saddling up for a horseback ride along the Atlantic. So the following day, I find myself sloshing down a muddy residential road toward Cas En Bas beach, accompanied by three cheerful guides who buoy my companions and me along with their mantra, "St. Lucia . . . no pressure, no problems!"

When the tree-lined path opens up to reveal a wide swath of sand licked by the sea, I see what they mean. It's a Sunday afternoon, and the beach is filled with families enjoying their leisure. Men and boys grunt good-naturedly over a game of cricket while children splash in the ocean.

Stripping down to our bathing suits as our guides remove the saddles, we ride bareback into the waves, gliding through the bathwater-warm water right up to the horses' chests. It's exactly as I imagined - except that, in my mind's eye, I looked a heck of a lot more like Bo Derek than I do in the photos snapped by my friends.

But my aquatic adventures aren't over. St. Lucia boasts a multitude of dramatic dive sites, ranging from a freighter sunk in 60 feet of water near Anse Cochon to coral reefs sloping from 20 feet to 145 feet off the coast of Anse Chastanet.

As an inexperienced diver, I opt for a shallower dive off Pigeon Point on the north end of the island led by a team from Sandals Grande St. Lucian. "I guarantee you're going to see lots of humans and lots of water today," assures Martin, one of two guides aboard our boat. Irwin, the second guide, goes so far as to promise a few fish.

We are not disappointed. Shortly after we take a giant stride into the clear, tepid water, Irwin spots a puffer fish darting among the coral. The puffer's tiny fins, which seem comically small for his fat little body, flutter daintily at his sides as his googly eyes gape at our trail of bubbles, seemingly as curious about us as we are about him.

I hear the crunch-crunch-crunch of rainbow-colored parrot fish munching coral as a school of little blue chromis arrive to escort me through their neighborhood. Then the current picks up, and I'm flying through the water, the reef unfolding below me like a crazy quilt of colors and textures.

I struggle to take in all the details - Christmas tree worms clinging to the coral; the intricate folds of sponges that remind me of giant clams in the Pacific; a sleeper goby, the biggest I've ever seen, hunkered down like a bodyguard outside a shrimp's hole.

When we suddenly find ourselves swimming against the current, which repels us as powerfully as an invisible force field, Irwin signals that it's time to go up. Reluctantly, I begin my slow ascent toward the surface, as charmed by St. Lucia's sun-dappled depths as I was by the peaks of the Pitons.