MIAMI -- At 15, Phoebe Mills was a member of the U.S. Olympic gymnastics team, tumbling her way to a medal in Seoul.

Now 17, she's part of another team -- in high school -- and in a different sport.

Mills has traded her gymnast's leotard for a swimsuit, the balance beam for a springboard, chalk dust for chlorinated water. After winning a national championship and the McDonald's American Cup in 1988, plus a bronze medal on the balance beam at the 1988 Summer Olympics, she gave up the sport that exhausted her and started diving for fun.

She carries the air of a relaxed, unharried high school student in a sport that she hasn't quite mastered, and that's fine with her. She has no Olympic aspirations in her new sport. At least not yet.

Instead of grueling eight-hour stints in a gym, Mills gets to enjoy summer activities, like the two weeks at a diving camp at the Mission Bay Aquatic Center in Boca Raton, Fla. She practiced with other divers in the morning and early afternoon, then quit at 3 p.m. and went to the hotel where everyone stayed.

"A girl on my diving team told me about" the camp, Mills said. "Everyone here has been really nice. I haven't been treated any different."

Mills still draws a lot of attention -- former Olympians have something of a lingering mystique -- even at a site frequented by Olympic medalists. While at the camp, reporters and photographers swarmed around her, eager to talk with the girl who captured the bronze. She was always gracious, always smiling.

"You learn to live with it," she said, shrugging.

But Mills couldn't live with the strain of competitive gymnastics. While training in Houston, she missed her home and family in Illinois. She felt that she was behind on schoolwork and was constantly worn out.

"I had been sick, and that made it difficult to train," she said. "It really made it pretty hard to work out."

That led to her decision to quit gymnastics in early 1989. But by summer, she had decided she didn't want to languish at home either. The solution was to go back into sports, and the logical choice was diving. It's not unusual for gymnasts to switch to diving, but it is startling for an established Olympic gymnast to start all over in a different sport.

"We're seeing more and more of that," said Ron O'Brien, head diving coach at Mission Bay and one of Mills's coaches. "They finish with gymnastics at such an early age, they can switch to another sport. They still have quite a few athletic years ahead of them."

Mills's diving career started last summer when she joined the junior varsity at New Trier High School in Winnetka, Ill. In just her first year of competitive diving, Mills finished second in the conference junior varsity meet.

That's part of the reason Mills likes diving. She's starting from the bottom and working her way up.

"She's doing well, extremely well, for the short time she's been diving," O'Brien said. "She's good enough to go to college on a scholarship."

"It's a lot of fun," Mills said. "It's something that gives me motivation. In gymnastics I was at the highest level. In diving I'm starting from scratch. It's more appealing because there's a goal I could set."

This goal is not as lofty as the Olympics. What Mills wants now is to become good enough to earn a scholarship.

"I don't want to achieve the same level as I had in gymnastics. That was a lot of pressure. I'm not saying this won't change, because I don't know," she said.

Mills is not completely removed from gymnastics. She said she still watches meets on television and has nothing but praise for this year's national champion, Kim Zmeskal. This summer, she will coach for a few days at gymnastics camps in Massachusetts and Colorado.

She hasn't thought about what colleges she'd like to go to, only that she would like to go.

"If there was anything left, I would have stuck with it," Mills said. "I went to the Olympics, and on top of it, I got a medal. I'm really pleased with how it turned out."