Like a flock of wounded birds, vacationers from the Northeast descended on St. Thomas last week, seeking refuge from snowbound disasters. For some, it was enough to bake on a beach, with tropical tradewinds blowing through palm trees overhead.

But for the more adventurous, these islands--which Columbus was the first European to see, in 1493--provide an opportunity for the safest and most accessible encounters with wildlife in the civilized world. For $4, you can rent a mask, flippers and rubber breathing tube, propel yourself a few yards offshore and see what Jacques Cousteau sees when he goes on vacation.

Snorkeling is to the Caribbean what standup comics are to the Catskills. Imagine yourself in a giant, saltwater aquarium, swimming in a school of parrotfish with bodies that shimmer silver, yellow and green and whose lips are painted a bright blue. Below you is pink, elkhorn coral shaped like elephant's ears. A few more kicks and you are over half a dozen other types of coral, starfish, squid, seafans, sponges and sea urchins.

"The only dangerous thing about snorkeling here is that people get so absorbed in what they're looking at, they don't pay attention to where they're going," said a lifeguard at Trunk Bay beach on St. John Island. "By the time they look up, they're halfway to South America."

These islands have a long history of mesmerizing people, both because of their beauty and because of their strategic position. The earliest known inhabitants were Arawak Indians. They were driven out by the Caribs, a cannibalistic tribe that left only their names behind shortly after the first Spanish explorers swashbuckled ashore in the 16th Century.

For the next few hundred years, the Spanish, French, English, Dutch and Danes raised and lowered their flags over the 1,600 islands, islets and cays that form the northern boundary of the Caribbean Sea. The United States bought 50 of the islands for $25 million, including three of the biggest--St. Thomas, St. Croix and St. John--in 1917 to keep them out of German hands.

Until 1848, when the Danish governor outlawed slavery on the islands, St. Thomas was the largest slave market in the world. There are still ruins of sugar cane plantations on the islands.

St. Thomas, which is home to about 40,000 people, is 32 square miles of suicidal roads and breathtaking views. St. John, which is a 15-minute ferry ride from St. Thomas, is less than half the size of that island, and about twice as beautiful. Two-thirds of the island is national park. The 9,500 acres of land and 5,650 acres of surrounding water make it the smallest of the natural area national parks of the United States.

At Trunk Bay, the coral reef is so close to shore, you can virtually wade to it. What is more amazing is how unconcerned the exotic sea life seems to be to the hulking presence of so many splashing flippers. Float for five minutes above the coral and you will discover that what looked like brightly colored rock is actually a colony of living things--walking, swimming and waving in the currents.

Before you sell the family station wagon and book a flight, there is one cautionary note. Vacations here are hell coming home from.