Firm Fixes Pools Without Draining Them : Maintenance: Underwater Unlimited makes structural repairs on back-yard plunges without wasting water.

Except for a little pounding and a lot of bubbles, Margaret Mynders hardly heard or saw the worker who recently spent five hours ripping rusted steel out of her swimming pool.

That’s because he showed up in a wet suit instead of overalls, and all the noise stayed submerged. He was one of the divers from Underwater Unlimited Inc., which has developed a technique for repairing swimming pools without draining them. Divers spend hours in pools tearing out damaged areas and replacing them with a specially developed, plaster-based patch.

“All you could hear is when he pounded out the old cement. . . . It’s so marvelous because you are not inconvenienced a bit,” Mynders said.

There’s also the novelty value of having a scuba diver hanging out in the concrete pond for five hours. “I took a picture, but it didn’t come out very good,” the Newport Beach resident said.

Underwater Unlimited is the brainchild of Kevin Wallace, a former probation officer, and chemist Shawn Evans. One day in 1984, Evans showed Wallace a type of pool patch he had developed that could be applied underwater.

“I went and saw what he did,” Wallace said. “Not only did this stuff work, but (Evans) could blend it with surrounding material so you could not even tell it was done.” He joined Evans in starting the business.

Fixing pools underwater spares homeowners the risk of damage to the plaster when it dries and the possibility that the whole concrete shell might float out of the ground if the water table is high. And it saves the cost and trouble of having to refill, according to Wallace.

Working part time, Wallace said, he and Evans each earned about $20,000 from pool patches in the first year. The outfit has grown every year since to the point that it now has revenue of about $500,000 annually and has six employees.

Though the corporate office is in San Diego, Wallace said, a significant number of the jobs are in Orange County. He said his crews have fixed cracks or rust spots in hotel pools in the San Diego area, at UC San Diego and that Disneyland--with all its moats, lakes and pools--has expressed an interest.

Most jobs involve rust, with the steel reinforcement bars that make up the skeleton of a swimming pool either poking through the concrete finish or rusting beneath it. In a process that Wallace compares to being an “underwater dentist,” wet-suited workers chisel through concrete and saw away rusted steel. They then apply the patch, which has an agent that dries it solidly to the steel.

The typical job, he said, takes about three or four hours and costs about $300.

Richard Riegler said he heard about Underwater Unlimited through a pool supply store near his San Clemente home. He said he liked the idea of not having to drain his pool for the second time in a year to make repairs.

Underwater Unlimited patched a 12-foot crack without having to pull the plug.

Divers are sometimes used to perform ink tests to find leaks in pools but are not called in very often because of the added expense, said Jim McCloskey, editor of Pool and Spa News, a trade publication based in Los Angeles.

Draining pools is common because the expense of refilling, even at the height of the drought, was hardly ever more than $25--environmental considerations aside, McCloskey said. But Underwater Unlimited seems to have found an unusual specialty, though, and is developing a good reputation in the pool business, he said.

“It’s one of those things where they have a better mousetrap.”