YOU GET TO KEEP YOUR SOCKS ON WHEN YOU GO SKINNY-DIPPING IN ANTARCTICA

The hole in the ice was seven feet long and three feet wide, about the size of a coffin. Loose ice lay scattered around it where the sadists and masochists of Vanda Station, Antarctica had flung it in their enthusiasm while digging. Perhaps it was just my imagination, but already a thin sheet of ice appeared to be forming on the surface of the surly blue-green water in the hole, the only wet part of Lake Vanda showing. But there was no chance of a reprieve. The helicopter pilot standing next to me, a red-headed, taciturn man named Randy Rothchild, was already stripping off his long Johns. He was a methodical person; unemotional, almost sedate. His skin was very white.

I pushed back the hood of my parka. The wind nipped at my ears. I took off the parka and put it lovingly down on the rocks of the lake shore. There was a chance I might live to need it again. I unfastened my belt. The only items of clothing the rules allow are socks. They keep your feet from sticking to the ice.

It was summer in Antarctica. At McMurdo Station, U.S. headquarters on the frozen continent, the mercury had soared to 25° Fahrenheit, sunbathing weather by Antarctic standards. Here, at Vanda Station, 75 air miles northwest of McMurdo, which is occupied from October to February by four jovial New Zealand scientists who, for good reason, call themselves Vandals, the temperature was 15°, and there was a 10-knot wind blowing down from the great ice plateau of the interior. The water temperature at the surface of Lake Vanda was 38°. Until this moment I had had one simple goal: To get warm. I was on my way back to McMurdo from a field camp in an adjacent valley, where I had been watching two scientists study the wind erosion of rocks. My own project was an article for Smithsonian magazine, but after four days of manipulating bits of metal and rock with freezing fingers and shivering over a pathetically small stove inside a four-poster Scott tent—named for the English explorer Robert Falcon Scott, who froze to death in one of them—I was entirely preoccupied with thoughts of hot showers, saunas and the bliss of McMurdo's notoriously overheated "California Hotel." The helicopter that had picked me up stopped at Vanda Station for another passenger, tempting fate. And fate had sprung its trap: The Vandals had dug their swimming hole just that morning.

It was not as if I had any choice. Elsewhere I could have declined the honor. Every place that freezes, from Buffalo to Duluth to Nome, has its goosebump swimmers, but, like triathletes, they are kept at a safe distance by the kind of derision heaped upon them by those of us less fit or brave. Some are organized into mutual support groups called Polar Bear or Penguin clubs, but membership is entirely voluntary (SI, Dec. 22-29, 1980).

But in Antarctica, immersion in cold is a compulsion. Since the 1840s, historian Roland Huntford has written, polar exploration has been "a moral source of suffering," but today, what with well-insulated buildings and gourmet mess halls, explorers in search of true pain sometimes have to help things along. Even those who have no icy water available make do. Winter residents at the U.S.'s Amundsen-Scott Station at the South Pole, where the continental ice sheet is 9,000 feet thick, call their organization the Three Hundred Club. On the first day of winter that the thermometer drops below—100° they crank the sauna up to 200°, get in and cook, then dash outside and run around the stake that marks the Pole. Though most Polar Bear clubs in civilized places permit bathing suits, Antarctica is stark: At the Pole, as at Vanda, the only clothing allowed is footgear.

Antarctica's tradition of nude bathing was probably started by the Australian explorer Douglas Mawson. One day in early 1912, members of his expedition to the south magnetic pole found that a box they thought contained vital stove parts had fallen into seven feet of 30° seawater. Mawson, who has been described as "tall and powerful, a commanding leader," stripped and plunged, rescuing the box after three dives.

Mawson, who went on to endure much greater suffering, has been immortalized by, among other things, having his name given to an Antarctic cod—Dissostichus mawsoni—a large, lugubrious-looking fish that, scientists have recently discovered, has a type of antifreeze in its system. But his plunge also established a standard of futility that Vanda swimmers nobly uphold: The precious box of "stove parts" contained four dozen tins of Australian jam instead.

When Mawson climbed out of the water he said with a grin, "It was not a bit exhilarating." In Antarctica one lives surrounded by the words of famous men, and another phrase that seemed appropriate as I removed my shirt was written by Scott when he knew, in his tent, that he was doomed: "We shall die like gentlemen," he wrote. At Vanda the swimming-club book contains a whole pageful of rules such as "1. No togs allowed"; "4. Complete immersion must be achieved"; "6. No restriction on photography." But the most important is unwritten. Although women now make up about 10% of the personnel at McMurdo and some have even joined the Royal Vanda Swimming Club, the continent is still, as one explorer titled his book in 1968, A World of Men and of straightforward male virtues. The unwritten Vanda rule is simple: A gentleman, presented with the opportunity to swim, swims.

So we did. Rothchild walked calmly to the hole. He carefully adjusted the sign the Vandals had put up—an old swimming-safety poster displaying a buxom beauty and the legend EVERYBODY NEEDS A BUDDY. While the Vandals looked on, he stepped down into the water, the first American to join the club this summer and one of only a hundred or so individuals of various nationalities who will join it all year.

It took but a second. Rothchild submerged in about four feet of water—and came up a different man. He leaped to the surface of the ice. He shouted. He uttered expletives. He ran to the shore. He flung clothing around, trying to get arms and legs into it all at once. And then it was my turn.

Mawson is said to have begun his plunge "without a word." I was up to that, at least. My jaws were locked. I nodded to the Vandals, who seemed unduly amused. I glanced at the small pile of clothing I was leaving. I would return. I stepped in and sank, and then I, too, underwent a profound psychological and philosophical conversion. I gained insight, understanding and resolve. As the green water closed over my head I knew that all the mistakes I had made in my life had led inexorably to this moment and that at last and forever, whatever other foolishness I should commit in the future would never come close to this.