The Vashon Park District will open the pool for one  day of free swimming on Saturday, rain or shine.

The event, organizers say, is meant to thank the community for supporting the pool, provide information on the upcoming extended season and allow the Friends of Vashon Pool to preview their vision for a covered pool.

Pool manager Scott Bonney has promised to heat the locker rooms as well as the water.

“I’ll crank it up to 88 or 90 degrees,” he said. “You can jump in with steam rising off the pool.”

Representatives from the Friends of the Vashon Pool will be on hand to discuss their work, recruit new volunteers and let people know about the swimming season, which will go through September this year. They will also discuss their efforts to make swimming throughout the year possible at the public pool — an effort that has taken place repeatedly since the pool was first built in 1974.

The Friends of the Vashon Pool came together at the end of last summer, disappointed that the outdoor swimming season was drawing to a close. Since then, they have secured a commitment from the park district to extend the season this year and have been researching pool enclosure possibilities. Now, Bob McMahon, a member of the group, said they believe a retractable, transparent enclosure that could open and close is the best option, and they worked with island architect Charlie Choo, who created the rendering shown here to convey possibilities.

However, there is considerable work to do before such a vision could become a reality.

A consultant is evaluating the pool this week to determine what work there is essential. Already, McMahon said, they know some tiles are damaged, the deck is cracked, the boiler needs work and the piping system is deteriorating.

“Those are improvements that need to be made whether or not it is enclosed,” he said.

Also, before the pool could be used for competition, the shallow end must be 6 inches deeper, a change that could be made by revamping the gutter system.

In all, he said, the friends group is looking to determine what needs to be done so the pool could be used for another 30 years or more. The group is working toward making  a proposal to the park district this fall, regarding cost and potential time lines.

On Saturday, admission will be free for lap swimmers from 11 a.m. to 1 p.m. and for recreational swimmers from 1 to 3 p.m. There will be music, games, hot soup and hot chocolate. Early bird, discounted season passes will also be sold.