Gary Xavier sweeps his arm in a wide arc, taking in a chunk of ocean that touches Tortola on one side and St. John on the other: ''This whole channel is easy to navigate. You can't get lost. Pick any beach, break out your mask and snorkel. Bring a picnic and some cold drinks.''

Xavier owns Awesome Power Boat Rentals in Red Hook, the marina town on the east end of St. Thomas. His boats are 22- and 26-foot center consoles with outboards and Bimini tops for shade that he rents to people looking to chart their own adventure. Touring the outside of the island by boat means I can pack in a dozen beaches in less than a day. For the aquatically oriented, it's love at first sight. For me, it's the perfect start to my week on St. Thomas.

Leaving Red Hook, we bounce across Pillsbury Sound on top of a light chop, seeing things that are invisible from the road: multimillion-dollar villas dangling at the edge of the steep cliffs, pelicans diving within feet of the boat, the big cross looming above Cruz Bay.

''This is Trunk Bay,'' Xavier notes, pointing to the famous day-trip destination. A forest of snorkels breaks the chop like a wolfpack of U-boat periscopes stalking unwary freighters. We motor around the corner and he idles the little boat into the protected arms of Hawksnest Bay. The water around us is gloriously deserted. ''The snorkeling's just as good here, and you have it to yourself,'' he says.

The warm, shallow water rings a perfect white-sand beach. Swimming in and around the reefs that thrive here, I find damselfish and squid, parrotfish and trumpetfish and large elkhorn coral. And I don't have to share them with anyone.

BRITISH INVASION
We cruise down the length of St. John passing Cinnamon Bay, Francis Bay and Leinster Bay, then Xavier cuts the wheel to the left and heads toward the British Virgin Islands. Jost Van Dyke and our destination, Sidney's Peace & Love, is all of 10 minutes away. There's a certain kind of hunger that comes from snorkeling under a tropical sun. Fortunately, we're right around the corner from one of the best places in all the Virgins to satisfy a salty appetite.

As we idle up to the dock, Sidney comes out of the low-slung open-air building to greet us. ''I told him about your lobster,'' Xavier shouts.

''Oh, Lord, yeah,'' Sidney answers. ''We got lobster.''

He disappears, returning with two of the biggest Caribbean lobsters I've ever seen above or below water. The monsters are a full 2 feet from snout to tail, their antennae adding another eye-poking yard to their total length.

Sidney cooks the lobsters to perfection over an open fire, serving them with mounds of peas and rice and coleslaw. A collection of T-shirts tacked up by past guests dangle from the ceiling. Xavier tells me that it's packed here on Thursday nights when The Awesome 02 Band performs for the all-you-can-eat lobster dinner. I keep my shirt on, but vow to come back for more lobster or a heaping plate of pork at one of Sidney's infamous Monday and Saturday pig roasts.

Back out in the sound, the smooth water has attracted a flotilla of sailboats, fishing boats and luxury yachts, each headed for their own secret spot among the islets. A squadron of Jet Skis catches us from behind. With their hair streaming and throttles wide open, the riders' faces are all sunglasses and smiles as they blow past us.

VENI VIDI VISA
When I get downtown, Charlotte Amalie's shops are buzzing. A tax-free port since the time of the Danes, St. Thomas was built to trade — literally. Many of the downtown stores are located in 300-year-old warehouses that have faced fires, hurricanes and other calamities without giving an inch. Short on bricks, the Danes learned to use them only for parts of the buildings that needed the most support. Doors and windows are framed in brick, while the spaces in between are filled with local stone. Constructed to safeguard cotton, tobacco and rum, they now contain more conventional goodies.

I start at A.H. Riise — a retailer with roots that reach back more than a century — which holds down a whole block between the waterfront and Main Street. It's the Nordstrom's of duty-free, offering everything from jewelry to Rolex watches to loose stones and custom settings. The Jewels boutique within A.H. Riise has an exclusive collection: David Yurman, Patek Philippe, Tiffany, Mikimoto. There is not one, but two Little Switzerland stores to further slake your thirst for fine jewelry and precious pieces from Lladró and Waterford, among others. Cardow, with two stores on Main, plus three others, has a broad selection of jewelry and loose stones and a 100-foot ''buffet'' case of gold chains. In Colombian Emeralds International, I peruse the crystal, watches and china before diving into what the store is best known for — emeralds direct from Colombia, along with diamonds and tanzanite.

While most of the retailers have two or three stores, Diamonds International has nine locations in St. Thomas. The surging popularity of tanzanite — a rarity just a few years ago — has spurred many jewelers to stock it and has spawned a specialty store, Tanzanite International. Looking into a case filled with a field of the gems in colors ranging from a pale peridot to near about midnight, it's easy to understand the almost magnetic pull this African stone has over Caribbean shoppers.

There's also a full-blown market for local products, especially art. The cool passageways of the Royal Dane Mall open into the Jonna White Gallery on Main Street. White has lived in St. Thomas for three decades, and her fine art prints are astonishing in their detail and inventiveness. Rich, multilayer images suggest the island atmosphere but don't fall into the easy clichés of sunsets and sailboats.

A few feet away, the sidewalk is a torrent of pedestrians. The shops are closing, the keepers scurrying away. Day-trippers from the mammoth cruise ships are flowing back to the docks, shopping bags bobbing from either hand.

I head out into a spectacular sunset, the light playing off the hull of a 70-foot yacht, Luck of the Irish, backed up to the seawall just in front of the Mall.

Even after spending a day downtown, I haven't gotten my fill of history or unique Danish architecture, so I decide to head up to Mahogany Run to dine at the Old Stone Farmhouse. Once part of a sprawling sugar plantation, the building now houses one of the island's top restaurants.

St. Thomas chefs long ago branched out into Continental, French and Italian cuisines and, more recently, into fusion menus. At the Old Stone Farmhouse, French-Asian is the order of the day, and I'm anxious to sample something by the new chef.

Inside, subdued lighting picks up the sheen of light-colored wood floors. The 19th-century patchwork stone walls are typical Danish construction. Several large dining rooms are connected by arches outlined in brick.

The restaurant breathes antiquity. The menu does not. Since Julia and Brian Katz opened the restaurant, it has embraced everything from cold-water seafood to sushi. Service is perfect — there when you want and not when you don't — and though the food has tropical undertones, you may forget you're in the Caribbean. There are Prince Edward Island mussels in coconut milk and

ale, duck with plantains and a ginger plum wine sauce and sushi. The best of whatever the local fisherman caught today is paired with fresh greens, reductions and purées made with tropical fruits and vegetables. If the ice cream hadn't been homemade I swear I wouldn't have ordered it, but how could I leave without at least having a taste?

BOOGIE NIGHTS
I'm headed for the only place to properly end a night on St. Thomas: Duffy's Love Shack. Duffy's isn't anywhere near town; it's out by Red Hook, and you'd be forgiven for thinking it was a farmer's stand or a flea market if you saw it in the daytime.

The Shack is in a parking lot, the roof supported by poles and beams and the walls open on two sides. It's an arrangement that acknowledges the inevitable: If the walls weren't open, the party would have blown them off and spilled outside anyway.

As I pull up, the sound system is cranked and it's happy hour — at midnight. A buck for a Greenie and a precious unoccupied bar stool give me everything I need for close-quarters observation. The mixed crowd is shaking it up on the dance floor. Being close to the marinas and the ferry dock, you're never quite sure who's going to show up. The guy in the khaki shorts and sandals shaking it down next to the brunette in the Capri pants could be a spring-breaker, or he could be just passing through while moving his yacht from Nevis back to Newport for the summer. Around the building's perimeter, tables are packed with giggly coeds. The girls ogle tattooed guys in baggy shorts and suck down Volcanoes, Duffy's 50-ounce power potion. The guys ogle the girls and drink whatever is closest at hand. It's a good bet this party will still be popping at the official 2 a.m. closing time.

DIVING DAYS
Pillsbury Sound, which separates St. Thomas and St. John, has a ripping tide, but that encourages the growth of the sponges and delicate feather-duster worms that coat the rocks around the cays in the shallow basin. Drift diving around Mongo, Thatch or Little St. James is a like taking a roller coaster through an exhibit of Jackson Pollock's color-splashed canvases. Red and orange coralline algae cover the rocks with a quilt of living color, and in between, little guys — grunts, squirrelfish, even baby eels — hide from the moving water.

The most popular wreck dive here is the General Rogers, a former buoy tender. There are other wrecks: The West Indies Trader, near the airport, is my personal favorite. A grain ship whose hull burst after water got into the cargo and made it swell, the WIT Shoal (as it's marked on the maps) comes to within 40 feet of the surface. The holds are open for exploration, and you may even find a shark stowed away in one of the dark corners. The orange cup corals on the rear deck often have their tentacles fully extended even during the day, waiting for food to drift by.

Another day on the water has peaked my appetite, so I head for Gladys'. It's not all that easy to find. The Royal Dane Mall is right on the waterfront, but the former warehouse is narrow, and the ancient brick walls on either side seem to close in above you. Down the long corridor and through a double arch, the café is cool, its left side lit by teak-framed windows. Floored with wide planks, the main room is backed by a mahogany bar. Slow jazz plays in the background, and over it a soft woman's voice is counterpointing ''The Street Where You Live.'' The voice belongs to Gladys, who superintends behind the bar, occasionally piping up to underline a phrase. Gladys is a handsome West Indian woman of a certain age; a quartet of photos over the bar depict her in stage garb; as a sultry silhouette; posing for a glamour portrait; and in a short skirt with head thrown back à la Tina Turner.

Gladys is chiefly celebrated on St. Thomas for her hot sauce, which she makes on the premises. I spill a little on my fried grouper, peas and rice. The heat brings out the nutty flavor in the rice and intensifies the spices coating the grouper. It takes a couple of Red Stripes to tame the flames, but there's nothing like Gladys' authentic West Indian cooking: coconut milk and callaloo, fried grouper and conch salad.

TOP OF THE MORNING
At 7 a.m., there's little traffic on the road that corkscrews up Skyline Drive. Though I'm not a morning person, the way the sun slants across the ocean in the early hours gets me moving. Skyline winds up to the top of the island, and soon enough I'm at St. Peter Greathouse, a rebuilt plantation manor with views of most of the north shore. It's closed, of course, and I wait until a worker invites me in. I don't want the tour or the lunch, I just want to stand on one of the balconies cantilevered over the steep landscaped slopes and stare.

Hans Lollick is out there, and Inner and Outer Brass islands. The ocean is a Paisley swirl of turquoise and blue shot through with flickers of gold. I point a telescope down toward Magens Bay, the beach empty at this hour. I scour the long eastern arm, the rocky border leading out to the narrow opening of the bay and follow the flights of pelicans diving for breakfast.

I see a few taxis beginning to ferry in the day-trippers who'll pool up at the east end. And I see the long, blank stretch to the west where I'm going to end this trip with a snorkel in waters teeming with baby tropicals followed by a well-deserved collapse on the beach. It's not high times, high culture or hauté cuisine, but after days filled with the best St. Thomas has to offer, the perfect way to end my trip is to become part of the scenery.

Posted online 07/25/02.