At about 2 a.m. on Memorial Day 1967. William W. Warner, a weekend sailor, was awakened from a deep sleep in the cockpit of his boat, which was moored off Smith Island in the Chesapeake Bay.

It was the beginning of another soft crab run for the Bay watermen "and all of a sudden great numbers of them were out working their floats" pulling up the 30-pound pots full of recently moulted blue crabs in the few hours before their new shells would begin to harden.

It was also the beginning of a new career for Warner, 56, an ex-foreign serive officer who refers to himself self-deprecatingly as "a bio-politician and scientist manque."

Warner was honored recently by Phi Beta Kappa, America's most venerable society for the promotion of excellence in the liberal arts and sciences, for his first book. "Beautiful Swimmers. Watermen, Crabs and the Chesapeake Bay."

The committee that recommended "Beautiful Swimmers" for the $2,500 science-writing award, said, "It is beautifully prepared and presents the whole natural history of the crab plus serious lessons of ecology and even anthropology."

Warner, who settled for a geology major at Princeton because at the time he attended there was no anthropology major, said over a trout breakfast at the Williamsburg Inn that the closest he got to anthropology was "a course in the history of man-101."

After graduating from Princeton Warner served in the Navy in the Pacific, ran a ski lodge and taught English in Stowe, Vt., and attended Columbia Teacher's College where, he said, "they taught you everything except how to teach English."

He subsequently "drifted down to Washington," went to work for the United States Information Agency and was assigned to a series of posts at U.S. cultural centers in Latin America.

Warner was serving in Guatemala in 1954 when the Communist government of Jacob Arbenz was overthrown in a coup engineered by the Central Intelligence Agency. USIS posts have traditionally served as covers for CIA agents, but Warner says he was "a straight arrow" and had no connection with the agency.

After that Warner worked at the Smithsonian Institution as assistant secretary for public service and then as the institution's top fund-raiser. He is currently on leave and working on another book on the worldwide revolution in commercial fishing.

Since returning to Washington from Latin America one of his greatest sources of pleasure has been "getting down to the Bay and away from the throng."

In the process Warner discovered a whole new world, with a different ecology, ethos and ehtic from the one he fled each weekend. It was the world of the Bay and Callinectessa sapidus Rathbun, the Atlantic blue crab.

He became involved not only with the Bay itself, its animal life and vegetation, its depths, currents and temperatures, but with the hard-working men and women whose lives and live-lihoods depend on its cycles.

In his acceptance speech Warner told two stories to illustrate the difficulty of winning the confidence of watermen and ohter representatives of the Bay culture.

"Once when I was lost in Dorchester County looking for a place called Best Pitch, which the inhabitiants call Base Bridge," he said. "I found a trapper's hut and asked the man inside if he could give me directions.

"Honey," he said, 'you ain't lost. Found your way in here, you did. You can just as well find your way out.'"

The other story involved a retired waterman in Tylertown on Smith Island who was also a bird carver. He knew Warner worked for the Smithsonian and asked him if he could find a print of a bald eagle that he could work from.

Warner came back, instead, with a stuffed golden eagle, which he found in a basement at the Smithsonian. Shortly thereafter the waterman offered Warner a gift of a bird carving and here Warner's training as a diplomat perhaps led him astray.

He said to the waterman, "Oh no, I couldn't," as one would to a South American host who offered you anything in his home your eye happened to fall upon.

"The next day," Warner said, "he [the waterman] wouldn't speak to me and he hasn't since. But the story may have a happy ending. There are intermediaries working on it." Warner is still a believer in diplomacy.

He finds his new life "rather lonely." Most of his writing in the past, he said, "was ghosting for my government bosses."

Warner said he "found a nifty little hideaway in the Audubon Society in Bethesda, which overlooked the largest magnolia tree in greater Washington." Headded, however, that the quiet was "narcotic" and he forced himself to go downtown once a week for lunch.

The book, he said, "has done well beyond my wildest dreams - 22,000 copies sold as of September and Penguin Books has bought the paperback rights."

But perhaps most satisfying of all, Warner said, is the "a lot of the watermen have written to say, 'You told it right.'"