Portable pool outside the Robert Egger Sr. Recreation Center

Kiki Ayala watched her five-year-old foster son splash around in the roughly constructed above-ground swimming pool outside the Robert Egger Sr. Recreation Center last week.

San Diego's Department of Park and Recreation hauls around and sets up three portable pools at five rec centers where kids otherwise don't have access to city pools.

Jaime and nine other kids, all under the age of six, were getting their first swimming lessons, supervised by two lifeguards.

"He loves this but I think he's swallowing too much water," Ayala said. "They have a really good teacher and he feels safe here." The pool will be here, near the border between San Diego and Imperial Beach, until mid-July, when it will be disassembled and moved to another rec center.

This week, a similar pool gets set up for a three-week run at the Adams rec center in Normal Heights. (Portable pools are also coming to Paradise Hills, Linda Vista, and Ocean Beach later in July and August.)

The Egger site is one of the most popular, according to parks spokesman Tim Graham, who said that about 950 kids each year learn swimming basics in the portable pools. The pools take at least two days to set up and tear down, he said. They measure 26 feet by 16 feet and are 3 feet deep, filled with about 7200 gallons of water — which weighs about 30 tons. So, the pool is sturdy, a thick, hard plastic set into a steel frame.

At the end of the session, parks workers will drain the pool water into a vacuum tanker truck and use the water for irrigation, Graham said.

Jaime learned how to float on his back last week — a basic skill that's frightening at first. The instructor held him and began to let go for seconds, reassuring him he was doing well and paying attention. (Classes are given according to kids' ages: two each for three- to five-year-olds, six- to eight-year-olds, and nine- to eleven-year-olds.)

"He's doing great," Ayala said. "The teacher is so good with the kids and makes them feel safe so this isn't so scary. She even makes waves in the little pool so the kids can see what being in the surf feels like."

The classes, which cost $10 for five lessons, are much less expensive than the regular fee of $56 for eight lessons at city pools.

Lifeguard Alejandro Castaneda watched over the ten kids in the pool.

"Because the cost for lessons is so low, a lot of kids come who've never been in lessons before," Castaneda said. "So you're actually teaching something new, something that can save their lives."

The five lessons focus on the basics, he said, including getting kids used to the water, teaching them to hold their breath, to float and kick, and to dog-paddle.

"Those are things that really matter when you're around water," he said. "Even if they just fall in or get knocked down by a wave at the beach, knowing how to float instead of panicking can save their lives. Everything about swimming is built on those skills."

After the lessons end, the pool stays open for an hour for kids to play.

"This is the best part of my summer," Castaneda said, as he rinsed off kids off a hose before they climbed the ladder and jumped in. "At least the best part of my summer job."