RALEIGH, N.C., JULY 17 -- They dive from 30 feet up and enter the water at speeds in excess of 35 mph. Michelle Mitchell, the current world champion and 1984 Olympic silver medalist, says it is an event in which the slimmest of margins separates brilliance and disaster.

Today, 15-year-old Genna Weiss of Silver Spring, Md., was brilliant consistently enough to finish second in the preliminary round of platform diving at the U.S. Olympic Festival. She also demonstrated how quickly she's closing in on Mitchell, 25, the grand dame of the sport.

In the eight-round preliminaries from which the top 12 finishers advance to Sunday's finals, Weiss went from eighth to third place in the sixth round and passed Lori Rizzuto for second on the final dive to bring her total to 387.06 points. Mitchell won with 459.66 points.

Weiss's final dive, an inward 2 1/2 somersault, is one in which the athlete stands on the edge of the platform with her back to the water, jumps, throws her head forward, tucks her legs under her and revolves 2 1/2 times before entering the pool. As difficult as it sounds, it's not challenging enough, said her coach, Ron O'Brien.

"Right now, when Genna hits her entries, she has probably the best rip {splashless} entry of any woman in the U.S.," he said. "But she needs to increase her degree of difficulty if she wants to be more competitive with the top people in the world."

Weiss seems ready to ascend to world-class status. She took fourth place in the indoor nationals and shortly afterward moved to Boca Raton, Fla., to train with Olympic coach O'Brien. Her parents remained in Silver Spring; they drive to Florida twice a month to visit.

For Weiss, the past few months have been a whirlwind of activity. "But I had to do it," she said. "It was a hard decision, but why not go for the gold?"