Off the port bow, the late afternoon sea was suddenly boiling with thousands of sardines jumping out of the water.

Our guide, Cuco, a rugged fisherman with skin like old cowboy boots, steered in close. We were after whatever had scared the little fish to the surface.

We dropped a couple of lines into the water, and within minutes one of them doubled over like a cat's back. My daughter, Kate, reeled the line in as far as her 9-year-old arms would let her, and then she handed the rod off to our friend Hugh, who finished the job. When the fish got close enough, Cuco grabbed it by the tail -- no nets, no gaff, just his tough leathery hand -- and we cheered the flapping arrival of a yard-long, 16-pound yellow jack.

An hour later, the fish hit the dinner table at our island camp.

Andrea Tamagnini, an Italian campmaster and gourmet chef, had turned it into a silver platter of thinly sliced, blood-red sashimi, served with a bowl of fresh limes and a few drops of soy sauce. We ate it with chilled Sonoma Valley chardonnay by the light of hurricane lanterns, at a long wooden dinner table set with china and linen napkins, under a large tent pitched a few feet from the gently lapping surf.

"Whatever the sea provides," said Tamagnini, crunching a slice of the meaty fish, followed by ceviche made with an octopus caught in the shallow turquoise water maybe 50 yards from the dinner table.

Technically, the experience at Tamagnini's Baja Camp is "camping," the way that shoveling down a Dunkin' Donuts cruller is technically "dining."

What Tamagnini has created here, on a perfect strand on a completely unspoiled island in the middle of the Sea of Cortez, is something unique and luxurious. There are tents, but that's about all Baja Camp has in common with our family's previous experiences with roughing it in the wild.

Except for the camp and a few fishermen's shacks, the 38-square-mile Isla Espiritu Santo (Island of the Holy Spirit) is totally free of human interference. The island is a rare triumph of conservation and philanthropy in Mexico, where both concepts are relatively new. Last year, a group of Mexican and U.S. environmental groups, including the Nature Conservancy and the World Wildlife Fund, raised more than $3 million to buy out the group of local residents. Those local folks had perpetual rights to use the government-owned island under a system created after the 1910-17 Mexican Revolution to ensure that people who worked a plot of land had rights to it.

The locals had tried to evade strict regulations governing land use on islands in the Sea of Cortez by building a half-dozen concrete bungalows on the island's longest and most spectacular beach. That set off alarm bells with preservationists, who ultimately raised the millions to buy the rights to the island. The bungalows were destroyed and the preservationists turned over the island to the federal government for conservation. President Vicente Fox traveled to the island in January 2003 to sign the decree formalizing the deal, the first of its kind in Mexican history.

Now Espiritu Santo remains a sanctuary in the middle of the 800-mile-long Sea of Cortez, also known as the Gulf of California, which Jacques Cousteau once described as "the world's aquarium" because of its vast array of marine life, including whales, dolphins, sharks, manta rays, turtles and sea lions.

Tamagnini managed to navigate the complex bureaucratic barriers and won permission from the Mexican government to operate his camp, the only one of its kind in the Sea of Cortez, from May to October each year; he is now in his fourth season.

The vast majority of his customers have been Italians and other Europeans. A few Americans have come, but the camp has remained largely undiscovered by the throngs of U.S. tourists who come to Baja California. They generally gravitate toward the golf and deep-sea fishing offered a couple of hours down the peninsula in Los Cabos.

Tamagnini's camp sits on a stretch of white-sand beach called Ensenada del Candelero, about halfway up the island's western coast, facing the desert mainland of Baja -- about an hour's boat ride from the port city of La Paz and its international airport. The beach is at the head of a shallow cove of sparkling emerald water, protected on three sides by steep canyon walls of loose rock and tall green cactuses. The walls rise 300 feet or more, and in the soft light of sunrise and sunset they become huge canvases of pinks and greens and browns, linking perfect blue skies with the impossibly green and blue sea.

Camp Life

The camp has one main tent, about 20 by 25 feet, which is divided into a dining area, with a heavy wooden table that seats 10, and a living area with 10 reclining canvas deck chairs facing the water. Two huge coolers hold blocks of ice and drinks. Another tent at the back houses the camp kitchen, which has two huge freezers powered by solar panels, a full-size range with an oven and gas burners, a mesquite charcoal grill and all the tools Tamagnini and his crew of five need to prepare elegant meals in the style preferred by his Italian mother: simple, with light seasonings that let the fish and the pasta speak for themselves.

Set out along the beach are four guest tents (a fifth is available), each fitted with two single beds on wooden frames, with crisp fresh sheets and a light cotton spread, and a large wooden trunk for clothes. The tents have high ceilings that make it easy to walk around, and at 13 by 13 feet, they have plenty of extra room. Kate and our son, Tom, 7, decided that they'd rather bunk in with Mom and Dad than be in their own tent. But even with four beds in the tent, plus our luggage, we had plenty of space.

A shower stall and toilet are set behind each guest tent. The shower consists of a wooden platform in the sand, surrounded by six-foot-high canvas walls. Water, collected in a natural spring in the canyon at the back of the cove, falls from a bucket fitted with a shower head in its bottom, suspended on a rope overhead. For all of us, nothing felt better than a sun-heated shower of fresh water to wash off the salt and sand at the end of each day. In keeping with the island's strict environmental regulations, the toilet is another canvas enclosure with a small commode with plastic liners, which are emptied regularly.

It is the kind of place Tamagnini, 43, has wanted to create since he was a boy growing up in Mogadishu, Somalia. His grandparents went to Africa to flee Mussolini and his fascists, and Tamagnini lived there well into his teens. Every summer his family set up a safari-style tent camp on a remote beach, where he learned to love camping and catching his dinner in the sea -- often by spear-fishing.

Tamagnini still keeps his spear-gun handy. One afternoon during our three-day stay, we spotted hundreds of huge yellow jack darting about in the shallows right off the camp. We spent an hour chasing the fish in the camp's 26-foot launch and dropping Tamagnini into the middle of them. He hit one of them with a spear, but it managed to get away. Tamagnini shrugged -- whatever the sea provides, and sometimes it's stingy.

But never dull. My wife, Mary, and I and our kids, along with our friends Hugh and Cindy and their two boys -- the only overnight guests on the island -- spent hours every morning snorkeling among plenty of yellow, blue and green tropical fish. We took the camp's four ocean kayaks out every day, paddling to a couple of small islands where scores of pelicans eyed us curiously.

Each morning and afternoon, we hopped into the launch to see a different part of the island. One morning we found a pod of dolphins playing right in front of our boat. First we spotted two fins splitting the water, then four, then 10, then a dozen. They dove beneath the boat and came up on the other side, and we followed them until they finally swam off into deeper water. The look on the kids' faces was magical.

Barking Sea Lions,

Flipping Rays

Our favorite excursion was to Los Islotes, a group of small rocky islands off the northern tip of Isla La Partida, which is separated from Espiritu Santo by a narrow channel. There, hundreds of sea lions bark and play and sun themselves on the rocks. We anchored in the deep green water 25 yards off the biggest island. Hugh and I hopped in, towing our 7-year-old sons on their boogie boards. We paddled in close enough to the sea lions to hear them bark at us -- playfully, we hoped -- and a couple swam out to swish below us with remarkable grace.

On the way back to the camp, we stopped at a little fishermen's camp on the beach at El Rincon, in the channel between Espiritu Santo and La Partida, where we bought a fat yellow snapper out of an ice-filled cooler. After a few photos with the kids and the biggest fish they'd ever seen, we motored back to camp past soaring cliffs and rocky hills, while black-and-white manta rays jumped out of the water and looked like so many magpies flipping through the warm spring air.

The next morning we took a half-hour boat trip to Bonanza Beach, a nearly three-mile stretch of perfect white sand on the southeastern side of Espiritu Santo. Tamagnini and one of his guys set up umbrellas for us on the beach to provide a little shade from the searing sun, and we sat and read and tried to count the number of different colors of green and blue in the water. The beach was also covered with the most majestic array of shells any of us had ever seen. We picked up a few, careful to follow regulations about not taking too many. We swam and dozed and swam some more.

By lunchtime we were back in camp. We made sure of it. Only a fool would miss a meal at Baja Camp, where Italy meets the ocean, with Mexico adding its own special flavors. Lunches of homemade pizza thick with mozzarella and fresh tomatoes waited for the kids, while we feasted on a huge bowl of chilled salad -- some days just a simple lettuce and carrot mix, other days something fancier, like Tamagnini's concoction of lettuce, diced potato, corn, guacamole, carrots, tuna, parsley, balsamic vinegar and his family's elegant olive oil. One day he served a carpaccio of fresh shrimp with lime and onion, which we heaped on thick, warm fresh-baked foccacia just out of the oven.

Tamagnini will prepare whatever his guests request, and there have been plenty of steaks fired on the mesquite grill. But the specialty here is anything from the sea. The snapper we bought from the local fishermen was done on the grill, with a light sauce of olive oil, parsley and lime. The octopus ceviche was crisp and cool, served with guacamole and chips. We brought wine with us, but realized that the California chardonnay and pinot grigio sold at the camp for $15 a bottle was a better value than the bottles we had lugged with us.

For each of our three nights in the camp, we set out canvas chairs under the stars after the kids went to bed. We reclined them as far as they would go and looked up at the breathtaking, star-dappled sky, miles from the nearest electric light.

The afternoon we left, the launch slipped slowly off the beach and cut through the shallows into deeper and deeper water. We measured our goodbyes in deepening shades of green, as relaxed as any of us had ever been.

Kevin Sullivan and his wife, Mary Jordan, are The Post's Mexico City bureau chiefs.