MINNEAPOLIS, JULY 13 -- She is a world-class diver, an Olympic medalist, a veteran of her sport.

Wendy Lian Williams would seem to have it all. She models, she makes motivational speeches, she smiles and the world melts.

Williams is one of the superstars of the strong field in the diving competition at the U.S. Olympic Festival. Today, after winning the preliminary competition in the 10-meter platform with a score of 447.69, her best preliminary score ever, she said she is happy and loves her work. But she also told of a life that isn't all that it seems.

Yes, she does photo shoots and appears in magazine ads. But she also wonders how she is going to pay the rent on her tiny 1 1/2-room apartment in Laguna Beach, Calif., and frets that she may have to call her sisters for a loan. She would like to buy a new car to replace an ancient Volkswagen convertible bug, but she isn't certain how she'd make the payments.

"I have enough money now to make a down payment," she said, "but will I have the down payment in four months?"

The problem for Williams, as it is for many divers who are sticking around from 1988 to 1992, is that she has no sponsor, gets only a little money from the U.S. Olympic Committee and has no time for a full-time job.

"I don't know why I don't have a sponsor," she said. "People say to me, 'You're so photogenic. You speak well. They should be beating down your door.' I don't anticipate millions. I'd just like to pay my rent."

Williams receives around $1,000 a month from the USOC and U.S. Diving, which is her only salary. She wanted to live by the beach, so when she left the University of Miami and moved to Southern California to train, she rented a tiny place across the street from Laguna Beach. She has no air conditioning, lives on a busy, noisy street, and drew quizzical looks from her sisters when they came to visit and saw how small it was.

"I go a few months with no work and I wonder if I have to call my sisters and ask for help," she said. "I'm sort of a freelancer. Then I'll get a call and do a speech and I'll be okay for a while."

The modeling began for Mademoiselle magazine more than two years ago and continues sporadically.

"It's a fun and easy way to support myself enough to keep diving," she said.

But Williams, 23, knows she made the choice to stick with the sport -- and will live with it. In 1988, she sneaked into the top three on her final dive to win a surprising bronze medal on the platform at the Seoul Olympics. Now, she is burdened -- if that's the right word -- with marquee status in a sport searching for a new star in the wake of Greg Louganis's retirement.

"Don't do that to me," she warned reporters with a wagging index finger and a knowing laugh today. "I don't feel that it's a fact. I'm far from perfect. Greg was the greatest ever."

But she knows the pressure will be on to win another medal, perhaps gold, at the 1992 Barcelona Olympics.

"I'd be happy to go get another bronze medal," she said. "But I'd just be happy to make the team too. I am so happy with what I've done in my career, if something happened and I had to retire, I'd be really happy. When I stood there on the victory stand in Seoul, I told myself that this has surpassed my dreams. A lot of other people put gold medal aspirations on me, but I'm very happy with what I've done and would be happy just to go to another Olympics."

This is not to say she is simply going through the motions in these intervening years. Williams has made a concession to the leaders of this sport, the Chinese, by adding a new angle to two of her eight platform dives.

She is trying to end the dives by kicking out with her hands by her side and in effect, hanging flat out in the air before quickly reaching for the water. It's a move perfected by the Chinese, who snap through their spins and rip their entries into the water better than any other divers. If Williams perfects that move, she should enhance her prospects for a gold medal at the upcoming Goodwill Games in Seattle, and, down the road, the Olympics.

When she stands up at the top of that platform, or, even worse, does a handstand with her eyes looking down to the water 33 feet below, Williams is not fearless. She is scared.

"If I haven't slept a lot or if my self-confidence is kind of low, I have to remind myself that I've been up there how many hundreds of times and I tell that voice inside of me to shut up," she said. "But you do think about it."

With the finals of her event coming up Sunday, Williams said she is "relaxed," a rare feeling for a competitor in this nerve-jangling sport.

"The best part of the sport," Williams said, "is showing off and putting on a good show." Lowery Takes Silver

Kevin Lowery of Alexandria received a silver medal in Division II Sailboarding on Lake Minnetonka in Minneapolis today after the resolution of a protest in Thursday's event. He placed first twice and fourth three times in the seven-race regatta, finishing with 42 points. He finished behind Dan Kerckhoff of Naples, Fla., who had 19.40 points. Lowery edged Eric Nelson of Norfolk, who had 48.10 points. . . .

Rob Stull of Damascus, Md., is the leader after two events of the modern pentathlon. Rob's younger brother, Doug, is in third place after the fencing and swimming portions of the competition. Rob, a 1988 Olympian, set a festival record in the fencing competition. . . .

Debbi Lawrence of Kenosha, Wis., broke her U.S. record in the 10-kilometer race walk and two-time Olympian Carl Schueler won a 20-kilometer event that wound up being less than 20 kilometers.

Lawrence finished her race in 46 minutes 10.26 seconds, breaking the mark of 46:14.4 she set in The Athletics Congress meet June 15. She also beat the festival record of 47:54.0 set by Maryanne Torrellas of Clinton, Conn., in 1987.

The 20-kilometer course was inadvertently laid out for 18.230 kilometers when turnaround cones were misplaced at the marker for a 2 1/2-kilometer loop. Schueler, of Colorado Springs, won the race in 1:18:59.