If you're intimidated by the idea of an adventurer, if it conjures up images of some great, hulking macho type bloated on his own achievements, you ought to meet Gerry Clark from Kerikeri, New Zealand. He'll restore your faith in the gentle virtues of the adventuring man.

Clark was in the States last week to receive the Cruising Club of America's Blue Water Medal for outstanding achievement by an ocean sailor and to give a talk at the Smithsonian. But his story is about more than boats and the sea.

Clark, 60, spent over a decade on a waterborne mission to help creatures he has admired all his life -- sea birds. The first seven years was devoted to hand-building his vessel, a 31-foot cutter-rigged sloop fashioned from the kauri pine of his native island.

Then for 3 1/2 years Clark circumnavigated Antarctica, going from frigid island to frigid island around the Antarctic Circle to get a handle on dwindling populations of shearwaters, albatrosses, petrels, prions and other pelagic species.

It seems that man, in his quest to conquer, has brought a plague on parts of the earth's last frontier. Feral cats, offspring of pets abandoned at scientific and commercial exploration stations, and rats, imported unintentionally, are wreaking havoc with sea birds' nesting grounds, said Clark.

How much havoc? No one knew, and it was a hard job to begin gathering data to find out.

But not too hard for Clark, a diminutive, sparkling-eyed, soft-spoken fellow who decided to tackle it for the good of the world when he retired from a career in seafaring to run a small citrus orchard with his wife, Marge.

He built the little boat in a packing shed with the help of Marge and their four daughters, and he built it strong, mindful that it would face the most treacherous waters in the world in the latitudes seamen call the Roaring Forties and Furious Fifties.

It was the second sailboat he'd built, the first being a homemade plywood craft in which he circumnavigated New Zealand and sailed across the Tasman Sea to Australia.

On Feb. 21, 1983, Clark left Kerikeri with two temporary crew aboard, and that was the last New Zealand saw of him for 3 years 8 1/2 months, until he rolled back in on Nov. 6, 1986, with a lifetime of wilderness adventures under his belt and tomes of sea-bird data in hand.

He'd seen seas of 60 and 70 feet and weathered alone frigid winds of hurricane force. Twice his mast and sails had been carried away in storms. He'd rolled the boat a dozen times or more in the towering seas and was knocked down scores of times. Ice on deck nearly had sunk him with its weight.

He'd given himself up for doomed after the last and most vicious storm off the Kerguelen Islands, where seas of over 100 feet have been reported and where gale winds blow every day, on average.

But if you ask him what it was like, all in all, Clark will tell you modestly it had its moments, good and bad, and his fervent hope is that he can do something like it again.

The greatest pleasure? "Oh, definitely it was discovering a colony of birds where no one knew they existed," he said, like the blue petrels he found by camping in the rocks atop Cape Horn, or the 200,000 sooty shearwaters and 30,000 black-browed albatrosses he found on islands off Chile.

The places Clark visited are on no tour guide's list: the Falklands and South Georgia in the South Atlantic, where he spent two winters; the Crozets and Kerguelens, south of Madagascar; the South Sandwich Islands and Bouvetaya, the remotest piece of land on earth; MacDonald and Heard Islands, and finally Fremantle, Australia, where he limped in under makeshift rig to be greeted, to his astonishment, by the New Zealand America's Cup team, out practicing for their date with Dennis Conner and destiny.

By the time he reached Fremantle, Clark and his boat were so ravaged he was surprised to be alive. But a few days with his countrymen quickly fixed that. Michael Fay, head of the New Zealand challenge, greeted him in port and checked over his boat, which at the time was being propelled by a 12-foot stick of wood and a tarpaulin after the final dismasting.

"Can't have a Kiwi boat going out looking like that," Fay said, and set the New Zealand team to work helping the seafarer put his vessel right.

It was Fay, among others, who raised the money for Gerry and Marge Clark to fly to New York last week to collect the CCA award at the New York Yacht Club. The Antarctic voyage, largely self-financed, left the Clarks very nearly broke and he was planning to accept the plaque by mail.

Clark already has been awarded the Northland Harbor Board's Blue Water Medal in New Zealand, the Tilman Medal of the Royal Cruising Club of Great Britain and was named a Member of the British Empire by Queen Elizabeth for his Antarctic exploits.

But what he looks most fondly upon are the wild places he's been. Clark carried a revolving crew that numbered 22 by the time the voyage was over, as ornithologists and sailors joined him for different stretches. They stayed in the most astounding, severe, forgotten places.

On South Georgia, Clark watched albatrosses, which mate for life but go to sea for months at a time, reunited at their nests. What a spectacle, he said, to see them preen and flirt after a long stretch apart.

He anchored almost always in places where there was no sign man had ever been. "We've been most privileged to go to these places, really," he said.

Leopard seals and and elephant seals tried to sink the inflatable in which he made the treacherous passage from anchorage to shore.

When sailing offshore, Clark followed the line of Antarctic convergence, where bitter Antarctic waters meet the warmer currents from further north, creating nightmarish weather conditions. But "there is a great upwelling there," he said, and as food comes rolling to the surface, birds gather to feed.

He always counted birds, whether they were out to sea feeding or on the islands nesting or resting, and always on the islands he looked for signs of predation from cats and rats.

A curious mission. Why?

"I love birds, the sea and adventuring," said Clark, "and being retired, I had the opportunity. The only way to do it was in a small boat, so you can get places where a big boat can't go. Anyway, it was all we could afford to build."

The boat, Totorore, lies safely now in New Zealand's Bay of Islands, awaiting her next adventure. Clark has finished a book, "The Totorore Voyage," rich with photos as well as his prose, which is being published by Century-Hutchinson in New Zealand and should be out in the United States next year, though an American publisher hasn't been picked.

Meantime, he's hunting a new mission in the conservation-oriented research field. A Briton, Peter Harrison, is looking at bird life on subtropic Pacific islands, which might be a nice respite from the cold.

Said Clark: "I'd love to help."