It was midafternoon on our first day out when the baby whale decided to make friends with us.

We had set out that morning in our 14-foot Zodiac to get a closer look at the gray whales that each October leave the Bering Sea and migrate southward on a 6,000-mile ritual journey to the warm, shallow lagoons of the Baja Peninsula. Now a calf, resembling a partially submerged Volkswagen, had decided to swim up for a closer look at us.

This "baby" was 14 feet long and weighed about 1,500 pounds. And it wanted to play!

As the calf rocked gently beside us, one of the members of our group leaned over the edge of the Zodiac. Almost by reflex, she touched the whale's long, dark head. There was a startled look on the woman's face and she paused, just for an instant, before she realized what she had achieved. Then her arms flew straight up and she screamed in triumph.

But our encounter wasn't over. Just under the surface, we could clearly see the long, white shape of the whale's mother -- all 30 tons and 35 feet of maternal concern -- turn and head directly for her calf -- and our flimsy boat.

One plate-sized eye stared seriously at us as she made the pass. As we held our breath in terror and exhilaration, she slowly -- very slowly -- glided beneath our boat. She seemed endless. One flip of her tail fluke and we would have capsized.

Then, as suddenly as they had appeared, mother and calf were gone.

Our encounter confirmed all we hadheard about the phenomenon of the "friendly whales" of San Ignacio Lagoon. The gray whales who winter there have, within the past decade, begun to approach boaters with seeming curiosity and peaceful overtures. These friendly whales are found only in San Ignacio Lagoon; whales who winter elsewhere, experts say, do not display this behavior.

To see the phenomenon for ourselves, we had traveled to the lagoon -- on the Pacific coast of Baja California Sur, Mexico -- for a seven-day whale-watching and camping expedition. Hundreds of the gray whales congregate here each winter, to mate, bear their young and train them for the long return journey to their arctic summer feeding grounds.

When we arrived at sunset at our village of tents on the shore of the isolated, 60-square-mile lagoon, hundreds of brant geese rose from wide, shell-strewn tidal flats to fly in long lines along the shore. It was a fitting welcome to what we were to find was a naturalist's paradise.

We knew that for four days we would be in sleeping bags; we would have no showers, newspapers or telephones. Our one luxury was a solar-powered flush toilet, a joy promptly dubbed "The Moon Palace." But even battered by the winds that sweep in from the Pacific, our group of 14 was comfortable and in a state of constant exhilaration. We were high on whales.

Life in camp took on a rhythm. Each evening, Mexican villagers, including the local delgado (mayor), arrived with the glowing sunset to visit "Mas Cafe'," the 30-foot tent that served as our combination dining hall, cantina and study hall. They brought us gifts -- fresh scallops, rare seashells, deer antlers to decorate our tent. We shared Mexican beer. Sometimes they brought along a shy wife or child.

Breakfasts were leisurely. There was time to explore tide pools and mangrove estuaries while our group leaders scanned the lagoon with binoculars, waiting for the chop to go down.

When the "go" signal came, the heavy Zodiacs were launched and we were off to the lower lagoon. The shallow upper lagoon, a birthing and nursery area for baby whales, is off limits to tour boats.

Emerald green and glassy calm, the lower lagoon is ringed with low sand hills and rocky outcroppings. Hazy outlines of the Santa Clara Mountains form a backdrop for the vast and virtually empty lagoon.

Throttling the motor to neutral, providing a low throb to let the whales know our position, we waited. You do not go to whales. They come to you.

Then it came: "Whoosh." The sound was behind us. It came again. "Whoosh." From another direction, a breathy snort. "Whoosh . . . Whoosh . . . Whoosh." Our heads swiveled. From every compass point we could see the gleaming backs of gray whales as they paused, exhaled 15-foot-tall misty spouts and took slow slides beneath the sea.

During the next four days on the lagoon, we were often out of control emotionally. Polite strangers when we arrived, now we yelled, screamed and hugged. We snapped wildly with cameras at whales and dolphins who joined our play, leaping gracefully ahead in the bow wave of the Zodiacs. We had to take a vote on whether we would even stop on the beach for lunch.

Whalers used to call the gray whales "devilfish" because of their aggressive ferocity. Only a dozen years ago, boats were overturned by suspicious whales at the slightest indication the intruder was an enemy. The whales did not bother the local fishermen, but "word got around" when danger threatened.

But 11 years ago, all that changed. Whale researcher Mary Lou Jones was the first to document contact with a friendly whale in San Ignacio lagoon, when a curious calf -- later nicknamed Amazing Grace -- approached her boat, possibly attracted by the outboard motor sound, and found friendly hands reaching out.

The next year more calves made approaches. A few years later, mother whales joined the gangs. The San Ignacio phenomenon seemed to confirm what studies have shown: that whales, the Earth's largest mammals, communicate with one another.

Gray whales -- distinguished by the blotchy white patches of barnacles and orange lice on their skin -- are baleen whales. Instead of teeth, they have hundreds of fringed plates hanging from their upper jaws, like a sieve. They "graze" on plankton and small aquatic animals.

Nineteenth-century whalers discovered their peaceful havens off the coast of Baja, and massacres in Mexican lagoons reduced the population to near extinction. Since given protection from whaling in 1937, they now number nearly 20,000 -- close to their original stock.

One of our group members was on his fourth trip to the lagoon, making him our certified whale nut. On an earlier trip, he told us, the whales had spent hours of friendly play around his skiff, rubbing against his boat, holding their heads up to be petted and scratched. Mothers and calves touched constantly, moving under and around his little boat.

Several times, he said, he observed a mother placing her calf on her back and then sliding the calf toward the skiff. "She wanted the calf to get acquainted with us," he theorized, still stunned by the experience.

We spent hours on the water watching the whales' acrobatics. They would "breach" -- make splendid leaps, flinging their bodies three-quarters out of the water -- and then crash heavily back into the sea. They executed "spy hops," pushing their heads straight up (sometimes by standing on their tails in shallow water) to take a look around, then sinking back into the sea. Sometimes the yell would go up, "Flukes at 3 o'clock!" A whale often showed its broad expanse of tail flukes, 10 to 12 feet across, before making a long dive, leaving behind a flat slick called a "whale print" on the surface.

Whales have always been alluring -- mysterious, fascinating and elusive, something to see only from afar. Now reports of "friendly" whales have made the Baja lagoons a magnet for tourists.

Most Baja excursions for whale-watching are by ship out of San Diego. Long-range fishing boats turn themselves into whale-watchers beginning in January, when the whales begin their return journey northward. Males and young adults head out of Baja first; mothers and calves remain behind until late March and early April.

Whale-watching in the Baja lagoons is closely regulated by the Mexican government. Three Pacific Coast lagoons have been declared official sanctuaries -- Ojo de Liebre (Scammon's Lagoon), Guerrero Negro and San Ignacio, the favorite for tour boats. Boats must have permits for specific days; only two tour boats may be in a lagoon at a time. They are allowed to put in three small skiffs. Passengers take turns for time on the water.

Because of the growing numbers of whale-watching boats during the migration season, there has been concern expressed about the whales.

But Steven L. Swartz, a gray-whale expert who has spent six winters at the San Ignacio Lagoon, said recently that he sees no problems with the tourist activity there. "The way the Mexican government is handling this -- limiting permits to responsible operators on specific days and for specific areas -- has not interfered, so far, with the whales' mating and calving environment," he said. Marian Cromley is a free-lance writer.

WAYS & MEANS

Baja's Frontier Tours, 2223 C St., San Diego, Calif. 92102, (619) 232-1600, is the only company licensed by Mexico to offer land camping whale-watching trips in San Ignacio Lagoon. Seven- or nine-day trips are offered, from Jan. 23 to April 3.

Trips begin in Loreto, on the east coast of the Baja peninsula, and include a 200-mile overland drive to the base camp in San Ignacio Lagoon. The cost is $885 (double occupancy) for a seven-day trip; that price includes camping equipment, the overland drive to the base camp, two nights in the Loreta La Pinta hotel in San Ignacio, and all meals (excluding hotel meals). A nine-day trip costs $1,185 (double occupancy) and includes an additional night at the La Pinta Hotel. Airfare is not included.

GETTING THERE:

From the Washington area, travel begins with a flight to Los Angeles for connection with Aero Mexico to Loreto, Baja California Sur, Mexico. The Mexican leg of the trip costs $218 round trip.

Half our group had flown into Loreto and were driven the final 200 miles to base camp, but my group caravaned to the village of San Ignacio from San Diego in four-wheel-drive vehicles. It was a fascinating 2 1/2-day drive on Mexico 1, Baja's famous transpeninsular highway. But this method should be considered an option only for those experienced in driving in Baja. The final 50 miles southwest from San Ignacio, one of Baja's most charming oasis towns, was a teeth-rattling, three-hour ride on a corrugated washboard of a road. One travel guide advises: "You will need a four-wheel-drive vehicle and should not attempt the 50-mile drive without inquiring at the grocery store or from other local merchants whether the road is passable."

WHEN TO GO:

With the final departure of whales in late April from San Ignacio Lagoon, Baja's Frontier Tours has five more trips scheduled. Seven-day trips are set for March 6, March 13, March 27 and April 3; a nine-day trip is scheduled March 19.

BOAT TRIPS:

Several long-range fishing boats berthed in San Diego schedule whale-watching expeditions to San Ignacio Lagoon. For information about schedules and costs, contact:

Fisherman's Landing, 2838 Garrison St., San Diego, Calif. 92106, (619) 222-0391.

H&M Landing, 2803 Emerson St., San Diego, Calif. 92106, (619) 222-1144.

SUGGESTED READING:

"Gray Whales: At Play in San Ignacio Lagoon," National Geographic, June 1987.

"Mothers and Calves," Oceans magazine, March 1984.

"Field Guide to the Gray Whale" (Legacy Publishing Co., 1442A Walnut St., #295, Berkeley, Calif. 94709).

"Baja Book III," by Tom Miller (Baja Trail Publications Inc., P.O. Box 6088, Huntington Beach, Calif. 92615).

Marian Cromley