‘This is hard to do, but it looks so beautiful.’

As recorded music from “Les Miserables” filled the air at the Torrance city pool, Benstead Plunge, young girls joined hands in the sparkling blue water and formed a star as they moved in a circle.

Later, they extended their legs above the water, much as ballet dancers might do on stage. In this case, though, the “dancers” slowly sank below the surface.

“That’s a barracuda,” said Kathy Bachus, a summer recreation instructor at the pool.

It wasn’t long before some of the girls shot out of the water with a little help from fellow swimmers, who gave them a boost. That wave-making maneuver is called a rocket, Bachus said, continuing her rundown on the basics of synchronized swimming.

She spoke as the youthful swimmers put the finishing touches on routines for this year’s edition of Torrance’s annual “Aquacade,” which will be presented tonight and Saturday at 8.

The show, which runs for more than an hour, is the culmination of eight weeks’ practice in which the 60 swimmers--girls between the ages of 7 and 20, except for one 10-year-old boy--mastered the techniques and movements with which to dazzle audiences.

“This is hard to do, but it looks so beautiful,” Bachus said. She describes the sport--which was popularized in the movies by Esther Williams--as a combination of swimming, dancing and aerobics.

“It takes flexibility, strength and endurance and they work so hard to do it,” she said.

Jill Whitson, who is the co-instructor with Bachus, sees synchronized swimming as more of an art form than a sport. “It’s expressing an idea to music,” she said. “You can’t do it without the music. It’s like dance.”

The biggest challenge to swimmers, she said, is to stay in formation. This requires listening carefully to the music and counting each beat--even underwater, where the sound is piped in. “They can’t really see when they’re in the water. They don’t know where people are and they have to know the music exactly,” she said.

Swimmer Lynne Whately of Redondo Beach says that if a swimmer makes a mistake, “you just smile and pretend that you’re supposed to be doing what you’re doing. You improvise.”

Bachus said one of the most difficult demands of synchronized swimming is rarely noticed by audiences because it happens underwater. These are the leg and arm movements swimmers use to support themselves as they gracefully move their hands or extend their legs.

The two instructors have choreographed this year’s show around the theme “Full of Life,” choosing music that includes pop songs and selections from movies and stage shows.

Whitson said: “The idea is a celebration of life. There are a lot of ups and downs in life, so why not live it to the fullest?”

There’s hot jazz, a comedy routine featuring pool lifeguards, and even a tribute to troops in the Persian Gulf War, with some girls holding American flags as they kick backward across the pool.

In some numbers, swimmers perform Latin or modern dance routines on the pool deck before diving into the water. “This is a show and we want it to look good,” Bachus said.

Added theatrical touches are achieved through lighting effects--including one in which only the performers’ white gloves and stockings will be visible--and a variety of costumes, ranging from sequined hats to cutaway coats.

The “Aquacade” was started with the opening of Benstead Plunge in 1956. It has become a traditional event in Torrance that often fills the pool’s bleachers.

“We’re the only aquacade around and there are people who expect it every year,” said city recreation coordinator Jeanne Gregory. “It’s artistic and upbeat, something that seems impossible to do but is made to look so easy.”

Whitson said the young swimmers are drawn to the aquacade because it’s a way to spend time with their friends during the summer and enjoy the thrill of performing.

“Maybe they don’t do plays and musicals,” she said. “The reward is their feeling that they really did accomplish something and they had fun at the same time.”

What: 36th Annual Aquacade.

When: Today, Saturday, 8 p.m.

Where: Benstead Plunge, 3331 Torrance Blvd., Torrance.

Admission: $3, adults; $1, seniors and children under 12.

Information: 618-2930.