Innovation drove pool manufacturer Robert G. Stark Sr.

Robert Gage Stark Sr., who pioneered molded fiberglass swimming pools and created water-filtration systems for zoos, aquariums and theme parks worldwide, was a tireless innovator.

At his Shoreline home, Mill Creek factory or faraway sites, he applied a rigorous work ethic to his endless flow of ideas.

He sold his San Juan Pools throughout the U.S. Their one-piece construction and easy installation made swimming pools more affordable.

He built Stark Aquatics Move able Bulkheads, fiberglass barriers that divide big civic pools into sections for diving or swimming. He also oversaw installation of his patented valves and water-purification systems at many theme parks, including Disney parks.

"His mother lived to age 95 and instilled in him an amazing work ethic," said his son Thomas Stark, of Kirkland. "He was definitely a self-made man who always ran the show. He was a loving father, too."

Mr. Stark died Monday (May 15) of renal cancer. He was 73.

The range of his hobbies showed his drive and imagination: He rode and raced horses, skied, golfed, fished, played tennis, and flew airplanes and hot-air balloons. He also had judged field trials for English pointer dogs.

Born in Texas, he moved to Seattle in the late 1940s. Skilled and self-taught in construction, he became a home contractor.

He always sought better ways to fix or build things. But he craved a real moneymaking invention.

Knowing the strength and plasticity of fiberglass boats, and that swimming pools were prohibitively expensive for the average homeowner, he formed San Juan Pool in 1957.

He made hundreds of pools each year. They cost from $7,000 to $10,000 installed, including diving board, pump and filter. A hole was dug one day, the pool was lowered into it the next, followed by sand washed around the perimeter to create a firm fit.

Rows of upended kidney-shaped and rectangular pools became a familiar sight at the Stark lot on the Bothell-Everett Highway in South Snohomish County.

Mr. Stark sold franchises for the pools nationwide.

He then got into developing efficient filtration systems and special valves to work with them. Stark Aquatic Systems were used for water in the film "Free Willy," at Disney World, in crab-rearing tanks at Chesapeake Bay and in sugar-cane fields of Hawaii.

"The filtration systems also are in use at Woodland Park Zoo and in water displays at the Luxor Hotel in Las Vegas," said Thomas Stark.

Mr. Stark sold his business last year, but son Robert Stark Jr. of Kenmore continues some manufacturing in Arlington.

Also surviving are Mr. Stark's wife of 53 years, Mary Ann Stark of Shoreline; his daughter, Janet Susan Stark of Edmonds; and seven grandchildren. His son John died in 1999, and his granddaughter Hayley died in 1986.

Services are today at 10 a.m. at Holyrood Catholic Cemetery, 205 N.E. 205th St., Shoreline.

Donations may go to the Juvenile Diabetes Foundation Guild of Greater Seattle, 1001 Fourth Ave., Seattle, WA 98154.

Carole Beers' e-mail address is cbeers@seattletimes.com