Two years ago, as the summer competitive swim season was getting under way, a former national champion backstroker named Barbara Stark Jordan decided to stop by a meet in Los Angeles to watch Natalie Coughlin race. Coughlin was nineteen then. She had just finished her sophomore year at the University of California at Berkeley, and people who follow swimming had begun comparing her to the greatest racers in history; some weeks earlier, in a flabbergasted account of one meet, the magazine Swimming World had described her performance record as “a tsunami that is sweeping everything before it.” Jordan swam in the 1952 Olympics, in Helsinki, and has coached and swum competitively throughout her adult life, so she knows exactly how fast certain racing times are—what it means, for example, to have backstroked a hundred yards in 49.97 seconds, which was one of the twenty-four American records that Coughlin had set during her first two years at Cal. “She was swimming so fast that it was hard for me to believe,” Jordan says.

Watching Natalie Coughlin swim in competition can be an unsettling experience. Even in one of the shiny ankle-length speed suits that racers often wear, Coughlin looks small and unimposing as she waits on the pool deck for the summons to the starting blocks. She’s slender, but not in a visibly athletic way, and although she’s five feet eight she seems shorter. The only time I’ve ever seen her shoulders ripple, she was hauling up a weighted pulley in a team workout room on the Cal campus; she says that if she lays off practice for more than a week her upper arms begin to shrink. (“That’s not me exaggerating,” Coughlin told me. “I look like this horrible, horrible swimmer, because I lose strength.”) She does have some framing advantages, such as unusually flexible limbs; during her shakeout routine at the blocks she is able to reach both arms straight behind her back, palms out, until her hands touch. There’s a loosening-up body shrug she performs, too, hopping up and down a few times on the pool deck, and she whips her bent arms over her head like a motorist trying to flag down help. She proceeds through these moves rapidly, soberly, breaking into a brief smile and waving to spectators when her name is announced. Then, if the race is backstroke, she makes a vertical line of her body and drops feet first into the pool.

Coughlin has broken six world records and thirty-five national records, and, in a sport that trains its stars to specialize in one or two strokes, her records encompass all four—freestyle, butterfly, backstroke, and individual medley, which requires a segment of breaststroke, her weakest stroke. (If she were a baseball player, this would be roughly the equivalent of batting .350, pitching a no-hitter, and setting a stolen-base record, all while playing against the best teams in the world.) But it is the backstroke, Coughlin’s signature race, that puts her most memorably on display. The backstroke racing start is both explosive and elegant: swimmers are taught to crouch against the pool wall, fists clenched around the metal handles of the starting blocks, before springing up out of the water and backward into the air. The hips rise, the body arcs, the reaching fingertips cut the water as cleanly as the tip of an arrow, and it is just after this point in the race that Coughlin, typically, vanishes.

I’ve seen spectators shake their heads in astonishment while Coughlin is underwater during a backstroke heat, or grab each other and gesture excitedly at the pool. The other racers have popped up already and are swimming hard, while the surface of Coughlin’s lane remains unbroken; from the poolside risers, if the swimmers’ kicking is not creating too much splash, a single streak of swimsuit is discernible deep below, like a glimpse of a river trout. When Coughlin finally appears, first her manicured hands and then the outstretched rest of her, she has almost invariably left her opponents behind. From then on, there often appear to be two separate events taking place in the pool—seven vigorous young women racing furiously against one another, and a languid, contemplative eighth person, her strokes slow and long, a body length or two ahead of everybody else. “It was absolutely beautiful,” Jordan told me, recalling the Los Angeles meet at which she first watched Coughlin win. “But, at the same time, I know what effort is going into it. I almost hold my breath with her. How she can power right into the stroke, after being under the water that long, is just unbelievable.”

By the time I met Jordan, this spring, at a Cal-Stanford meet in which Coughlin was dispatching her opponents in various distances of butterfly and freestyle, I had heard Coughlin’s swimming described not only as beautiful, which is something people frequently say about it, but also as a kayak slicing past rowboats, a ballet performed amid polka dancers, and a symphonic instrument tuned one octave lower than all the others. These were coaches’ metaphors, not sportswriters’; in recent months, coaches trying to explain to me what happens when Coughlin is in water have made reference to dolphins, cheetahs, gummy worms, screwdrivers, knives, javelins, bows, and the hockey player Gordie Howe. (“I grew up in Detroit,” the Oregon State University women’s swim coach, Larry Liebowitz, told me. “You learned to watch Gordie Howe, even without knowing anything about hockey, because the guy just flowed.”) The television swimming commentator Rowdy Gaines, who won three Olympic gold medals for the United States in 1984, has said that part of the reason he wants his children with him at the U.S. Olympic Trials this summer is so that they will be able to tell their grandchildren that they once saw Natalie Coughlin swim.

The Trials, which last for a week, begin on July 7th, in Long Beach, California, five weeks before the start of the Athens Olympics. A swimmer’s performance at the Trials is his or her sole route to the U.S. Olympic team—the sport’s highest glory—and, no matter how exceptional that swimmer’s recent record, Olympic spots are promised to only the first two finishers in each event final. The United States produces an abundance of fast swimmers, and many American coaches say that the U.S. Trials are the most competitive swim meet in the world—tougher than the Olympic Games, in terms of over-all pressure from the talented, and, in a way, contested for bigger stakes. A swimmer who doesn’t win a medal at the Olympics can still lay claim to having been an Olympian; there is no national recognition for those who try and fail at the Trials. Among the score of American swimmers who are most likely to win spots on the team this July, two are now widely regarded as once-in-a-generation, potentially-best-ever phenoms. One is a six-foot-four eighteen-year-old from Baltimore named Michael Phelps, who has already competed in one Olympics, broke five world records at the World Championships in Barcelona last summer, looks like a giant inverted triangle of muscle over elongated ropy legs, and has never, as far as is publicly known, had his advance toward international athletic stardom slowed by a single noteworthy setback or disappointment. The other is Natalie Coughlin.