Fire and water

Swimming to Antarctica: Tales of a Long-Distance Swimmer

By Lynne Cox

Knopf, 323 pp., $24.95

I mentioned to a friend that I was reviewing a memoir called "Swimming to Antarctica."

"Great title," she said. "What's it about?"

Well, it's about swimming. To Antarctica. Not that I blamed her for assuming the title was figurative. It does sound too preposterous to be anything else. And it has a terrific metaphorical ring to it, suggesting struggle, fortitude, endurance, triumph over impossible odds.

But Lynne Cox is an extraordinary athlete, and she is quite literally talking about descending into 32-degree water, wearing nothing but a Speedo, goggles, and a bathing cap, and swimming for a mile amid icebergs, leopard seals, and intense cold that would swiftly kill virtually any other human.

Cox's Antarctic swim in December 2002 was only the latest achievement in a 30-year career of pushing the physical and psychological limits of long-distance swimming. While still a child, she discovered that the rough conditions that drove other swimmers from the water -- storms, waves, cold temperatures -- exhilarated her and made her want to swim farther and faster. She started training in the Pacific Ocean, won the first few ocean races she entered, and decided, at the age of 15, to try the English Channel.

In an era when highly talented athletes are managed and agented and "handled," it's refreshing to read Cox's description of her innocent preparations for the trip: informally asking other swimmers for advice, cold-calling a boat pilot from a list of names, and finally taking a cab to Dover Beach with her mother on the morning of the swim (the cabdriver skeptically volunteered that she didn't look like a Channel swimmer because she was too fat). That night, she not only swam the Channel, she set a new world record. A year later, when her time was bested by a male swimmer, she returned and took the world record back, even though currents lengthened the swim by 3 miles. At this point, writes Cox with characteristic stunning simplicity, "I had had enough of swimming the English Channel; I wanted to do something else."

"Something else" was a series of boundary-shattering swims: battling fierce currents to cross New Zealand's Cook Strait; steering clear of gigantic whirlpools in the Strait of Magellan; rounding the Cape of Good Hope amid venomous sea snakes and man-eating sharks; punching her way through the ice of Alaska's Glacier Bay; and, in what Cox clearly considers the most important achievement of her life, becoming the first person to swim the Bering Strait, which she did in 1987 after 11 years of fighting for Soviet permission. It's a testament to Cox's motives and character that, upon completing this grueling swim, she chose diplomacy over physiology -- staying on the shore to talk to the Russian press and well-wishers (many of whom were in tears over the symbolic connection she'd just made between the two countries) rather than following urgent medical advice to get into a tent to start rewarming her body.

How has it been possible for Cox to complete so many unprecedented swims? How can she perform so strongly, and stay immersed for so long, in such cold water? Curious about these questions, Cox participated in a series of research experiments. Most female swimmers are so buoyant that they struggle to keep themselves below the surface of the water, while men generally have to fight their own negative buoyancy, or tendency to sink. Cox, however, has no buoyancy problems: Her ideal ratio of fat to muscle gives her body the same density as seawater. When she swims, she doesn't have to fight for proper position; all her energy is available to propel her forward.

Even more fascinating to scientists is her unique ability to tolerate extreme cold. For most people, any heat generated by swimming is canceled out by the catastrophic loss of heat from the cold water. Cox's swimming, in contrast, generates so much heat that even in frigid water, her core body temperature actually rises over the course of an hour's swim. She is a phenomenon. This isn't so much a story about what the human body is capable of: It's about what one unique body has been able to do, propelled by ambition and confidence and desire.

All this would make a great story even if Cox couldn't write. But she can. In prose that is lucid, clean, and powerful she evokes the physical and emotional experience of swimming. She describes the beauty of being in the ocean at night. "Flying fish the size of mockingbirds were leaping out of the water. They'd emerge from the depths and fly across the air, flapping their fins and sailing across the sky. . . . In the phosphorescent light, they were magically turning iridescent pink, blue, purple, rose, and green."

She is honest about the bad experiences of her career, with a nauseating account of swimming through raw sewage and dead rats in the Nile, and an equally vivid description of the horror and despair she felt when she got lost swimming in deep fog off Catalina Island. But most of the time, swimming for Cox equals "working hard, . . . drawing from every experience, learning how to feel the rhythm of the ocean, hear the tempo of the waves, and dance with the water using my balance, my strength, and all my senses."

Ultimately, Cox's memoir is about the joy of exploring the impossible. She's done things the rest of us can only imagine -- and she's written a book that helps us to imagine them with clarity and wonder.

Joan Wickersham is the author of "The Paper Anniversary." She lives in Cambridge.