The Viaduct Harbor here is lined with gleaming megayachts as the world's richest sports fans convene for the America's Cup. Here sits dark blue Independence, owned by Rich DeVos of Amway Corp. Here's Itasca, former U.S. Treasury Secretary William Simon's refurbished oceangoing tug. Here's snow-white Hyperion, a pleasure palace owned by Netscape founder Jim Clark.

In their midst squats an unpainted, bulbous, aluminum-hulled ugly duckling with the noblest purpose of all. It's the 120-foot, two-masted Antarctic Explorer of London, freshly commissioned under the auspices of the Cousteau Society and its new expeditions leader, Sir Peter Blake.

The Society has fallen on lean times since the death in 1997 of founder Jacques Cousteau. But Blake, the New Zealander who won every leg of the 1989-90 Whitbread 'Round the World Race, then set a world record by girdling the globe nonstop in the sailing catamaran Enza in 74 days, then topped it off by winning the America's Cup in 1995, has a new mission: To resurrect the Cousteau Society to worldwide prominence.

Antarctic Explorer is central to the plan. In it, Blake intends to roam the world's oceans reigniting interest in the sea and its environmental problems.

"What we want to do is to raise awareness of our name and ideals through television, the Internet, IMAX films and the like," Blake said, "and get people interested in the environment.

"There are more refugees escaping poor water quality today than fleeing war," he said. "We were sailing the Mediterranean coast off Spain recently and ran into an absolute stench. They were bulldozing rubbish from the city right off a cliff into the sea.

"I'm not a greenie," said Blake, 51, a towering figure at 6 feet 5 with a mop of shaggy blond hair. "I still drive a motorcar and fly in planes. But there are simple things everyone can do and we want to draw attention to them."

First there is the matter of defending the America's Cup, which he won as syndicate chief and crew member of Team New Zealand in San Diego five years ago. Blake was named a Knight of the British Empire after his triumph. He never intended to be part of the first Kiwi Cup defense but sponsors and organizers convinced him to serve as syndicate chief one last time.

He accepted and has kept busy for 4 1/2 years organizing the Cup Village and the Team New Zealand defense, but has been champing at the bit to finish ever since he was handpicked by the late Jacques-Yves Cousteau to succeed him in the head job at the Cousteau Society, pending completion of his Cup tasks.

Now the end is just a few weeks off and Blake is keener than ever to get going. He knows the oceans well, having competed in four Whitbreads before finally winning it as skipper of Steinlager II.

He said he personally witnessed a downturn in the sea's riches in his years offshore. "When we first sailed around the world in 1973, albatrosses were everywhere. Last time I went in 1994, we were lucky to see one a week."

Who cares about a decline in the population of the peculiar Antarctic birds with the nine-foot wingspan? "Maybe no one cares, but I do," huffed Blake. "I'm not satisfied to say, 'Man kills everything with no consequences.' I say the consequences are enormous. And pollution is happening today as never before.

"I want the Cousteau Society to be the environmental policeman of the seas. Today we have 100,000 members. I'd like to see one million in five years and five million soon after that. Then we can fund our mission as it should be."

Antarctic Explorer is one of two vessels the Society will initially use to spread the word. The other is Alcyon, an odd, 103-footer with two short turbo-masts that has been owned for years by the Society. Cousteau's original wooden dive boat, Calypso, is no longer in service. If the Society grows as planned, Blake hopes to have vessels on the prowl on every ocean.

Antarctic Explorer is a remarkably strong sailing ship that's rigged for strong winds and cold, high latitudes, with plate aluminum up to two inches thick in high-stress areas, retractable centerboards, tunnel drives for the propellers and a rounded hull so it will pop out of pack ice if it ever gets stuck. It was designed and built for French polar explorer Dr. Jean-Louis Etienne in 1989.

Blake hopes to take it to Greenland, through the Northwest Passage and on other Arctic and Antarctic adventures, and share the experiences through videos and the Internet.

"I've spent so much of my life at sea and seen changes that shouldn't be," Blake said. "Now it's time to do something, and quite quickly."

A charismatic character known throughout the sailing world for his bold assaults on the toughest yachting challenges, Blake won tremendous loyalty from his Whitbread crews, his record-setting round-the-world crew on the catamaran and his Kiwi mates in the America's Cup.

The plan now is to take his game to a grander, global scale. The armor for this knight's next battle may not shine like that of other yachts assembled here for the Cup, but Antarctic Explorer, he points out, is built for a purpose, not for fun.