By Janet Fullwood

But a summer vacation on St. John proved far from boring for us. We found plenty to do here, home to the only U.S. national park in the Caribbean.

"Not ANOTHER junior ranger program," our park-savvy kids groaned when told they'd be expected to participate in ranger-led walks, talks and other interpretive activities.

If you go Getting there: Cruz Bay, the main town on St. John, is accessible by ferry from two points on neighboring St. Thomas: Red Hook, at the island's east end, or downtown Charlotte Amalie, not far from the Havensight cruise ship facilities. Adult fares are $3 and $7, respectively; children travel to and from Red Hook for $1. Getting around: Public buses departing the Cruz Bay ferry terminal will drop you anywhere along the road to Coral Bay, at the far end of the island, for $1. The north shore road that services Cinnamon Bay, Trunk Bay, Maho Bay and most other beaches is served only by open-air "safari truck" taxis. Fares are per-person and vary according to how many people share the vehicle. To Cinnamon Bay, the standard rate with five or more passengers is $3.50 for adults, half-price for kids. Jeeps and similar four-wheel-drive vehicles are available for $50 to $70 per day. Island roads are narrow, twisty and often steep, and driving is on the left side of the road. Cinnamon Bay: Cinnamon Bay Campground offers bare sites, furnished tents and screened cottages, all just a short stroll from a mile-long, white sand beach. Rates fluctuate seasonally and range from $58 to $80 per night for furnished tents and $70 to $135 for cottages. Third and fourth occupants of a tent or cottage pay $15 per night extra. Bare sites are $25 year-round. Tents and cottages are furnished with beds, linens, propane stove, ice chest, picnic table and basic cooking equipment. Tenters also get a lantern; cottages have electric lights and fans. (A few also have dorm-size refrigerators.) A restaurant, commissary and water sports center are on the premises. The campground is often at 100 percent occupancy during the Dec. 15 to April 30 high season, with reservations required months in advance. Lowest occupancy is during August and September, the riskiest months for hurricanes. For more information or reservations: (800) 539-9998 or www.cinnamonbay.com. Maho Bay: Maho Bay Camps offers alternative lodging in a sprawling community of tent cottages built on a hillside above the namesake bay. A restaurant, beach and water sports center are on the premises. Rates are $70 per night, double occupancy, May 1-Dec. 14; $105 per night Dec. 15-April 30; and $115 per night during holiday periods. Children under 16 stay free May 1 through mid-November; there is a $12 per night charge for third and fourth persons the rest of the year. On the other side of the island, a more upscale camping resort, Concordia Eco-Tents, features such easy-on-the-environment touches as solar-powered fans and reading lights, and self-composting toilets. Maho's sibling properties include Harmony Studios and Estate Concordia Studios. Information on all is available at www.mahobay.com or by calling (800) 392-9004. Other lodging: St. John's other lodging choices include two upscale resorts, Caneel Bay and the Westin St. John, along with a variety of hotels, guesthouses and private homes for rent. Helpful Web sites include www.stjohnusvi.com, www.bookitvi.com and www.st-john.com. Virgin Islands National Park: Admission is free, but there is a $4 day-use fee for Trunk Bay and Annaberg ruins, and a $15 fee for the Reef Bay hike, which includes a boat ride from trail's end back to national park headquarters in Cruz Bay. For more park information, write to Virgin Islands National Park Headquarters, P.O. Box 710, Cruz Bay, St. John, V.I. 00830, or call (340) 776-6201. The official National Park Service site is www.nps.gov/viis. You'll find more information, including updated activity schedules, at www.virgin.islands.national-park.com. For information on the archaeology dig at Cinnamon Bay, go to www.friendsvinp.org.

Yet, when the time came, they were first in line to get a close-up look at a millipede, examine the fruit of the "stinking toe" tree or follow a ranger into the water to look under rocks for things like brittle stars and sea cucumbers.

"You're walking on fish poop," they gleefully informed us upon learning that a school of parrot fish, which chomp ceaselessly on the coral reef, can produce up to a ton of sand a year.

Education goes down easy when the subject of study is the tropical environment you've traveled almost a quarter of the way around the globe to reach. My husband, Daryl, and I had brought our family to St. John in summer — hurricane season as well as the off-season — because that's when we could get plane reservations using the frequent-flier tickets that had taken us years to earn.

A 5-inch downpour on the day of our arrival did not bode well for the weather.

"Hurricane come, we take you home with us," the woman behind the registration desk said when we arrived, dripping, at the national park's Cinnamon Bay Campground.

The weather turned out to be fine, as did our timing. A few days after we returned home in mid-August, Hurricane Debby threatened the Virgin Islands, veering off at the last minute to deliver only a glancing blow.

In any season, when you think of a Caribbean vacation, a hurricane of sand-and-sea images storms to mind, none of them, probably, having anything to do with national parks or camping.

Yet here we sit, slapping mosquitoes and sipping Top Ramen just steps from the turquoise sea that winks at us between palm trees. A beat-up aluminum coffee pot holds the dinner beverage: cherry Kool-Aid made with water fetched in a bucket from the communal spigot down the path. Calypso rhythms rollick from a pocket-size radio on the picnic table. Ripe fruit and distant rain scent the breeze.

William, 10, is curled in a hammock near the blazing white beach, immersed in the wizarding world of the fictional Harry Potter. Austin, 7, calls out to him in brotherly love, "Time to eat, dork."

Put a tropical twist on a family vacation, and what you get are some highly colorful memories made vivid if you're cooking your own meals on a propane camp stove, sharing a bathhouse with other families and sleeping to the sounds of the great outdoors, rather than to the hum of an air conditioner.

An overseas camping trip sounds like a lot of bother, but St. John, smallest and least populated of the three main U.S. Virgins, makes it easy. Two campgrounds, Cinnamon Bay and Maho Bay, take the edge off of roughing it by lodging guests in permanently pitched tents furnished with beds, ice chests and minimal equipment for cooking. Cinnamon Bay also has screened cottages for rent, which is what we chose to minimize the effects of temperamental summer weather.

For guests at either place, as for most travelers to St. John, the focus of a visit is Virgin Islands National Park, a glorious amalgam of white-sand beaches, fringing reefs, tropical forests and cultural relics that covers about three-fourths of the island's 19 square miles.

Prosperous St. John, population 5,000, is a mountainous and surprisingly diverse dot in the Leeward Islands. From its shores can be seen many of the other closely spaced islands and cays — Tortola, Jost van Dyke, Congo, Lovango, Mingo, Thatch, Great Thatch, Little and Great St. James — that draw sailors to this part of the Caribbean. Puerto Rico is 40 miles to the west, and St. Thomas is a looming presence reachable in just 20 minutes by ferry.

Yet most visitors to St. John find little reason to stray, for this agreeable place has it all in a tidy package. The island's scalloped north shore is rimmed with miles of the sort of beaches you might have thought existed only on doctored postcards. The surrounding sea is 82 degrees warm and so clear that visibility often tops 100 feet. Two towns, Cruz Bay and Coral Bay, offer diversion for those who want to eat out or shop. The national park is icing on the cake for those who like their scenery clean, green and uncommercialized.

A full sibling to Yellowstone and Yosemite, though hardly as well known, Virgin Islands National Park gets about 1 million visitors a year, many of them cruise ship passengers on excursions during a port call in St. Thomas. The park includes underwater acreage as well as 9,500 acres of land. It was established in 1956 on properties donated to the American people by various conservation concerns, in particular Laurance S. Rockefeller and his Jackson Hole Preserve. The wealthy philanthropist also built a luxury resort, Caneel Bay, that continues to enjoy a five-star, jacket-and-tie-for-dinner reputation.

Not far from Caneel Bay, the Cinnamon Bay campground rates five stars in its own right, especially for its location on an otherwise undeveloped mile-long beach. With its own restaurant, store and water sports center, the atmosphere is not so much that of a campground as of a seaside camping resort.

Maho Bay Camps, a few miles up the road on a private parcel surrounded by park land, is another congenial place especially popular with families. Accommodations are in cleverly designed platform tents that climb a steep hillside, connected to each other by boardwalks. The effect is like walking around in a giant, leafy tree house.

Our one-room Cinnamon Bay "cottage," in a fourplex of identical accommodations, had two concrete walls and two screen walls with curtains that could be closed for privacy.

Because the Caribbean is expensive, we filled our suitcases with few clothes but lots of groceries. These preparations proved fortuitous: The poorly stocked camp store offered milk at $2 a quart, and didn't get a delivery of bread until five days after our arrival. Restaurant service was curtailed for the off-season, with dinner available by arrangement, and then only between 4 and 5:30 p.m.

Since the round trip into Cruz Bay was $28 by taxi for the four of us, we didn't do much eating out. But we did rent a four-wheel-drive for a couple of days, which enabled us not only to go grocery shopping, but also to explore the island.

Traveling twisty, two-lane roads that alternately tunnel through forests and wind around ridgetops, we visited a variety of beaches and historic sites. A favorite stop was Annaberg Ruins, the remains of an 18th - century sugar plantation that the park service has restored and signed for self-guided tours.

A hike led by park ranger Laurel Brannick to remote Reef Bay introduced us to more island history, along with a host of marvelous things: bay rum trees and tyre palms, mongooses and wild donkeys, pre-Columbian petroglyphs and the ruins of two more sugar plantations dating from colonial times.

Along the way, Laurel painted verbal vignettes touching on everything from bush medicine to endangered species. In a memorable demonstration, she produced a seagrape leaf on which a message had been scratched with a twig. In the old days, she said, people used such leaves as writing tablets, or even to fashion decks of cards.

Another ranger-led hike took us along the mangrove-lined shore of Leinster Bay, where we spotted a baby shark, a barracuda with a fish in its mouth and an eagle ray, among other creatures. Back at the campground, there were slide show/lectures on sea turtles and creatures of the coral reef.

The reef itself is one of the primary attractions of St. John, and guests at Cinnamon Bay don't even have to leave the premises to enjoy it. We spent entire days on this beautiful strand, reading, building sand castles and visiting with people from Dallas and Miami, England and Puerto Rico, Canada, Oregon and New York. But mostly, we snorkeled, swimming amid angel fish and trigger fish, parrot fish and trumpet fish, blue tang, drum, doctor fish and other colorful species.

Without leaving the campground beach, we also were able to tour what is perhaps the most significant archaeological dig in progress in the Caribbean.

The site, in a seaside area threatened by erosion, has yielded evidence — beads, pottery, shells, sculpted representation of ancestral deities called zemis — of a Taino ceremonial site, the first of its kind ever found.

The Taino were the "Indians" who greeted Columbus on Puerto Rico and other islands in the central Caribbean, where their culture flourished for at least 1,000 years before Europeans wiped them out. Their memory survives in the words — potato, tomato, cotton, rubber, hammock, canoe, papaya, tobacco, hurricane, cassava — they gave the world, and in the petroglyphs they carved into boulders on St. John and other islands.

Ken Wild, the National Park Service archaeologist in charge of the dig, conducts tours of the findings twice a week, and invites volunteers to help sift, sort, catalog and otherwise assist on the project. About 3,000 volunteers donated their time last year, many of them Cinnamon Bay campers.

"This is an opportunity to be involved in an archaeological project of significant value," Wild said, "and it doesn't hurt that it's right on the beach, where you can jump in the water when it gets hot."

Jumping in the water is all most people think about when considering a Caribbean vacation. The charm of St. John, as our family learned, lies in its myriad additional possibilities.

Janet Fullwood is travel editor of the Sacramento Bee. Distributed by Universal Press Syndicate.