A Triumphant Return for Madame Butterfly : Swimming: A high school standout 50 years ago, Gloria Marienthal is nationally ranked in the Masters division.

When Gloria Marienthal left Park Forest, Ill., for Southern California 17 years ago, a friend jokingly told her that people who lived out there were required to swim twice a day.

“So I looked for the nearest Masters program and joined,” Marienthal said, laughing.

It was a move she hasn’t regretted. Last year, Marienthal ranked among the nation’s top 10 women’s swimmers in the 65-69 age group in the 100-meter butterfly (2:31.64), 200 butterfly (5:40.49), 1,500 freestyle (35:46.42) and 400 individual medley (10:05.32).

The times are particularly impressive because Marienthal, 66, doesn’t consider herself an overly competitive swimmer. But they are easy to understand once you realize Marienthal is a fighter, a survivor who overcame rectal cancer and who moved to California after her 29-year marriage ended in 1974.

Until that divorce, Marienthal’s life seemed charmed. Born in New York in 1925, Marienthal said she had a great time growing up there “when it was a neat place to be raised.”

From 1940-44, she attended Julia Richmond High School, then a 10,000-student all-girls school that served all of Manhattan. It was there that Marienthal began swimming seriously.

“My brother used to tease me that when I went to high school, I majored in swimming,” Marienthal said. “All my free time was spent at the pool.I did well in the meets, but back then the girls didn’t compete like they do now. I usually came in first or second. I did the sprints at that time.”

Two years after graduating, she married Frederic Marienthal, who eventually became an executive with Spiegel Inc. in Chicago and moved with his wife to Park Forest, a Chicago suburb.

The couple had three daughters and a son. Gloria Marienthal’s life centered around the children. She became involved in their school projects and in their swimming on the local YMCA team, where they all specialized in the butterfly events.

Marienthal and the children also spent time at a social and athletic club, where the youngsters swam and played and where Marienthal played cards with other women.

But her life wasn’t exactly material for “The Donna Reed Show.” By the time her youngest child was in college, Marienthal’s marriage had disintegrated. She decided to attend nursing school and graduated at 45. After her divorce, she headed west to begin a new life.

“I told my kids I was seeking the sun,” Marienthal said. “The weather is horrendous (in Chicago). The wind drove me up a wall.”

Marienthal spent her first year in California working in the Neuro Psychiatric Institute at the UCLA Medical Center and another year at the Scripps Clinic in La Jolla.

She moved to Orange County in 1979 and got a job as a facilities surveyor for the State Department of Health Services in Santa Ana. Her main duties were to inspect psychiatric hospitals and clinics whose licenses were up for renewal.

“I was very fortunate to get those jobs,” Marienthal said. “I had never worked before.”

She also hadn’t swam, at least not in a regimented setting, since high school. But she wanted to find a place where she could get back into the sport and socialize. Enter the Newport Beach Masters Swimming club.

Since 1981, Marienthal has been a member of the club, which now has 50 people. She practices with the group three times a week, either at the Newport Beach Tennis Club or at Corona del Mar High. And for the past year she has helped Dennis Skupinski coach the team, a task, Skupinski said, has benefited Marienthal.

“For her age, she’s fantastic--just to do some of those events even when you’re younger is a challenge,” Skupinski said. “I think that helping me coach has helped her concentrate more on her own swimming because now she doesn’t only have to know the techniques, but she has to get in the water and demonstrate them properly . . . I’ve noticed that she seems to have more incentive to go to the meets.”

Marienthal loves hanging around the Masters club. It was a source of comfort in 1984 when she underwent a colostomy and, she said, the members are a fun bunch to be around.

“It’s a very health-conscious group, but we also have parties at the drop of a hat,” she said.

Between parties, Marienthal volunteers her time with the CASA (Court-Appointed Special Advocate) program, working with children who have been removed from their homes for various reasons, and she puts in a lot of pool work. She swims between 2,000-4,000 yards per one-hour training session, concentrating primarily on the butterfly.

“The butterfly is fun, once you get the timing and the rhythm,” Marienthal said. “It took me two years to learn how to swim it properly. It’s not an easy stroke because you have to undulate. The whole stroke is in your hips. But I think it’s the prettiest to watch when it’s done right. The others (strokes) are so choppy.”

Marienthal is not the only one in her family to take up swimming at a senior age. Her mother, who for years had rejected Marienthal’s attempt to teach her how to swim, took the plunge at 65. She died at 90 three years ago.

“She finally got disgusted and went to the YMCA in New York and learned,” Marienthal said. “She lived in New York all her life. I could not get her to move out here.”

Too bad. Together, they could have swam twice a day in California.