Carlos Parsons was one of Washington's fortune-favored young for whom all the world and all of life is an adventure.

Born in Manila 24 years ago, a great-grandson of a Spanish-American War veteran, he had by the end of his 21st year sailed across the Atlantic, cruised the north coast of Africa, taught desert survival in Arizona, beachcombed atolls in the South Pacific, ridden rodeo bulls and played accomplished guitar.

A cum laude graduate of Landon School in Bethesda where he captained the track team, a National Merit scholarship semifinalist who went on to the University of Virginia, he sought out challenges, and by all accounts, laughed his way through them with a quiet, self-confident grace that spoke of nothing so much as promise.

Three weeks ago, while diving on a coral reef in the Philippines, Carlos Parsons vanished without a trace, leaving behind a mystery as exotic and strangely beautiful as his rich young life.

"It would have been easier had they found a body," his uncle, Peter Parsons, told mourners who packed Holy Trinity Catholic Church in Georgetown last week for a memorial service. "With Carlos we'll always be teased by that unexpressed tickle of hope that he may be alive somewhere . . . dancing on some distant shore."

Actually a body was found, but it turned out to be a local fisherman--still alive, in fact--shot in the arm, tossed overboard and then retrieved by comrades in an effort to claim a reward offered by the Parsons family. "They apparently thought any body would do," Peter Parsons explained.

Carlos James Parsons was, like a growing number of Washingtonians, the product of two cultures. His great-grandfather, after fighting in the Spanish-American War, returned to the Philippines as a trader and never left. His great-great uncle, Riccardo J. Alfaro, was president of Panama.

When World War II broke out, his grandfather, Charles (Chick) Parsons, was interned with his family in Manila until he persuaded the Japanese occupiers he was actually Panamanian and entitled to exchange as a diplomat. Ultimately he returned secretly by submarine as Gen. Douglas MacArthur's liaison with the Philippine guerrillas.

Carlos Parsons spent his first eight years in Manila where his father was a molasses broker. When his parents separated in 1967, he came to Washington with his mother to live near her parents, but returned to visit his father in the Philippines for months at a time. Other summer months he spent on a family farm in Denmark, or, as he grew into his teens, at the Orme School in Arizona where he learned rodeo and survival skills in a program similar to "Outward Bound."

"He was a remarkably cosmopolitan young man," remembers Somerville Parker, assistant headmaster at Landon School, which Carlos attended from the sixth grade. "Many young people are intimidated or overwhelmed by the pressures of adjustment in a divorce or a cultural change. But for those who overcome those pressures, they can be a strengthening force. Carlos seemed to handle it all very well."

Parker and other Landon teachers remember Carlos as a bright but quiet youth, an excellent student whose dark good looks, easy humor and charismatic smile drew others to him despite his natural shyness. He was also, friends say, "a very mature person, a genuine individualist" whose sharp wit and wide-ranging intellect combined with a zest for physical activity to inspire respect and affection from those around him.

"He was not a great athlete," remembers Paul Adkins, a close Landon friend. "But he loved running and worked at it so hard the track team elected him captain. And the rodeo stuff blew my mind. He was the first urban cowboy I ever knew."

At Virginia, his roommate David Johnson remembers, he lost the passion for grades, but not for ideas.

"There were three of us in the room--Carlos was Catholic, I was Protestant and the third guy was Jewish," remembers Johnson, a Phi Beta Kappa economics graduate now living in California. "We debated everything in theology--everything. Then Carlos got into astronomy and that got us into the whole theory of the universe. It was incredible. He opened so many vistas for me. I mean, we didn't just sit around drinking beer."

Parsons, says Johnson, "had read everything and remembered it all." He immersed himself further in music--from Shostakovich to the Grateful Dead--taking courses, buying record albums and sitting up nights with his stereo headphones on, playing his beloved guitar. From earlier fascinations with calculus and literature he branched out to major in environmental science. Johnson remembers his particular obsession with a course in tree growth.

"He thought he could use that if he went back to the Philippines," Johnson said. "He was interested in practical applications."

Carlos Parsons' mother, Mariana, had remarried. Her husband, Dr. Edward Fleming, was a Washington psychiatrist who made a fortune developing private psychiatric hospitals around the country. After early years in Spring Valley, they moved to Georgetown where they lived and entertained, Johnson recalls, "complete with guys in black tie passing champagne and the whole nine yards."

Parsons "was totally unpretentious about his family's wealth," Johnson remembers. "It seemed to amuse him. He thought it was fun."

He persuaded his stepfather to let him crew the summer of 1980 on one of four Fleming charter yachts, sailing the Atlantic to cruise the Greek Islands. But after Landon, another friend recalls, when his grandparents offered him any car he wanted for graduation, he chose a Honda. Later he sold it and invested the money.

"He could have lived with his mother and stepfather in pretty grand style," said John Katkish, a family friend, "but he always talked about going back to the Philippines. He said he'd give it a couple of years to see if he liked it."

He went back in 1981 as director of special projects for his father's company, the Asian Alcohol Corp., purchasing molasses and looking into new fuel sources and possible expansion for the company, which makes alcohol for Filipino rum and Japanese sake.

"It's a pretty big company," said Johnson, who visited him there last summer. "Carlos was traveling to Hong Kong, Thailand, Japan, New Zealand . . . . He really loved it."

He loved the Philippines, Johnson said. He and Johnson and former Virginia basketball star Lee Raker, another close friend, explored the back roads and villages of the islands in a Land Rover having, Johnson remembers, "as much fun as anybody can have."

One of the places they visited was a tiny island called Apo, southeast of Negros in the Mindanao Sea. "He told us it was one of the 10 top scuba-diving spots in the world," Johnson said. "He and Lee dove, but I had trouble with my ears."

Carlos had won his scuba certification at the University of Virginia and was an enthusiastic diver. "I dived with him in California and worried how he'd be in the ocean," Peter Parsons remembers. "But he was very good. He was even at home in kelp beds."

Carlos dived fairly regularly at Apo Island with his uncle Joe, a man in his mid-30s and an enthusiastic spear fisherman. On Jan. 14, after his return to the Philippines from a Christmas visit to Washington, they dived there again.

According to Peter Parsons, Carlos and Joe arrived off Apo Island about 11 a.m. in an outrigger canoe with an outboard motor and two Filipino boatmen. Along with their equipment and six tanks of air they brought spear guns. Carlos hoped to spear his first fish.

The reef 50 yards off Apo's northeastern tip is by all accounts a marine resource of incredible richness and beauty: a vast tropical aquarium where more than 80 species of fish, in huge multicolored schools, undulate among giant purple sponges, six-foot sea fans and coral heads fully 30 feet across.

Carlos and Joe went over the side into the 80-degree water in bright sunlight and swam slowly down the gently sloping reef searching for big amberjacks.

Carlos wore overalls for protection against the coral. His face mask, flippers and snorkel were standard, as was the regulator that adjusts air flow from tank to mouthpiece. A combination tank backpack, life vest and buoyancy compensator, made of orange nylon, fit over his shoulders and under his arms and could be partially inflated at the touch of a button to help achieve the desired neutral buoyancy.

"They went down to about 80 feet looking for big fish but didn't find any; descended to 120, then started back up immediately," Peter Parsons said. "At about 70 feet they encountered what Joe described to me as 'a huge river of fish' and they stayed there hunting."

Joe shot at a fish but missed, imbedding his spear in the coral. But Carlos finally got an amberjack of about 10 pounds and "was excited about it," Peter Parsons said.

Twenty minutes into the dive with about 700 pounds of air pressure left--well above the recommended 500-pound safety margin--Carlos signaled he was going up, taking his fish back to the boat. His uncle nodded and saw him start up through the shimmering river of fish, then turned away to free his own tangled spear. That took, he told Peter, less than a minute. Then he, too, started up.

When he reached the surface he found himself still upstream from the boat in the two-knot current. There was no sign of Carlos. The two Filipino boatmen said they hadn't seen him. They assumed he was still below.

The three men zigzagged the boat downstream for about 15 minutes in the southeast-flowing current, thinking Carlos might be using his remaining air near the surface while watching something below. Then Joe strapped on a new tank and went back in the water.

With an increasing sense of bewilderment and dread, he descended first to shallow depths and finally, risking the crippling or fatal effects of nitrogen bubbles in the bloodstream ("the bends"), he descended to 70 feet and then to 100 feet, searching fruitlessly in widening circles. In all, he used up four more tanks of air.

In the boat they combed the inlets of Apo and searched the beach. Then, with daylight and hope fading, they went for more help.

The next day as 10 volunteer divers searched the reef to depths of 200 feet, two Navy helicopters and six fixed-wing aircraft crisscrossed the 500 square mile waters of the Mindanao Sea. They found nothing. The search continued, fruitlessly, for a week. On Jan. 21, Carlos James Parsons was formally declared lost at sea.

Divers don't often vanish without a trace, and even the most plausible explanations for the disappearance remain unlikely. Peter Parsons, wry in his grief, frets at "the sense of incompleteness that will always be with us . . . the lingering hope . . . "

Carlos Parsons could conceivably have been crippled by a lung embolism from too rapid an ascent or disoriented by nitrogen narcosis, the "rapture of the deep," although the latter rarely affects divers above 100 feet.

It is also conceivable--but just barely--that he could have been struck by a shark lured by the blood from his speared fish. Sharks, however, almost never attack divers, are rarely seen at Apo and, with all the fish, would have had plenty to eat in any case.

"What sustained me was the thought that for some reason he had surfaced alive far beyond the boat and been swept by the current and the wind (12 to 15 knots northeasterly that day) into the sea between Negros and Mindanao," said Peter Parsons. "That's a hell of a big area with criss-crossing currents and confused seas that makes anything on the water hard to spot.

"I kept thinking that his wraparound life vest would provide some warmth and we'd ultimately find him holed up on some island somewhere."

David Johnson has had the same thought: "That would be sort of like Carlos, you know. He'd have a hut going. He'd have some project . . . And even if he never was found, he'd be interested in whatever was around him. If there were people there he'd be making them smile. And somehow, if you knew that, you'd be content."