Jacques Yves Cousteau, 1910-1997.

"The monumental problem for the future is overpopulation," an ebullient but angry Jacques Cousteau told E last year in an interview at the New York headquarters of the oceanic society that bears his name. Cousteau, who died in June at 87, believed that man-kind was in a race with time not just to reduce population, but also to prepare for the billions of new people who will inevitably be born.

"Even if we reduced the fertility of people now to two kids per family, we would still reach 10 billion in 45 years," he said. "But we can do one big thing: Open our arms and say to these 10 billion people, 'Welcome to this Earth.'"

Though Cousteau is best known as the charming and endlessly curious sea explorer who conquered American television in the 1960s and 70s, he was far more than a one-dimensional TV host. His invention of the aqualung and pioneering of underwater photography brought a previously unseen world into sharp focus. As Roger McManus, president of the Center for Marine Conservation, puts it, "It was through Jacques Cousteau's eyes that the world really saw the oceans for the first time."

But Cousteau had a restless intellect, and it wasn't confined to the undersea environment. In his latter years, he grew increasingly concerned about the future of life on Earth - because of runaway pollution, the nuclear threat, shrinking wildlife habitat and exploding population. "Our way of managing the Earth is wrong," he told E. "We need to outline what is possible and what is impossible with the non-renewable resources of the Earth."

Themes like these are the centerpiece of what the French daily newspaper Le Figaro called Cousteau's "final SOS for the planet," a 425 page autobiography called Man, Octopus and Orchid to be published in English this fall. "The book is his legacy," says Francine Triplet, Cousteau's second wife.

Part of that legacy was an increasingly deep pessimism. "The road to the future leads us smack into the wall," Cousteau writes. "We simply richochet off the alternatives that destiny offers: a demographic explosion that triggers social chaos and spreads death, nuclear delirium and the quasi-annihilation of the species. Our survival is no more than a question of 25, 50 or perhaps 100 years."

Greenpeace noted that Cousteau helped the public see beneath the surface of the ocean. His final message is that we should also see beyond our petty differences and come together to save the planet. CONTACT: The Cousteau Society, 870 Greenbrier Circle, Suite 402, Chesapeake, VA 23320/[phone].