MESA, Ariz. >> She’s a champion swimmer who didn’t learn to put her face in the water until she reached retirement age. She’s a world record holder but has only the vaguest notion of her fastest times. She’s a national champion in the backstroke who can tell you about the mechanics of the stroke but would rather rhapsodize about the heavenly view one gets, swimming with her back to the world, sunny side up.

Now the retired social worker, who didn’t swim her first serious lap until just before her 60th birthday, holds 16 age-group world records, 26 U.S. bests and dozens of national championship titles. Recently, at the U.S. Masters Swimming Spring National Championship, the late bloomer from the Hollywood Hills bagged six more titles.

At 97, Mo Kornfeld is the oldest active member of the 64,000- member U.S. Masters Swimming. The menagerie of former high school and college swimmers, onetime Olympians and aquatic latecomers swim for fitness and — if so inclined — in regional, national and international competitions.

On the first day of the championship meet in suburban Phoenix, a sunburned woman looked across the riot of wet, spandex-clad bodies and spotted Kornfeld: “There’s the queen.” Addressing nearly 2,000 swimmers and spectators roasting in 102-degree heat, the PA announcer called Kornfeld’s aquatic exploits “titanic.” Head referee Teri White deemed Kornfeld, simply, “the star of the meet.”

Her teammates on Pasadena’s Rose Bowl Masters swim team will regale you with stories of “Mighty Mo” — her ability to navigate two freeways to make workouts, her obliteration of most world records in the 95-99 age group, and the lowdown on the time she humbled a Frenchwoman who dared claim that she would be the dominant nonagenarian at the 2017 World Championships.

“That’s all very nice,” Kornfeld said of the effusive praise. “But, I mean, it’s only swimming. It’s not going to change the course of world events.”

Indeed, as much as her swimming comrades talk about her records, they speak more passionately about the Kornfeld they know from the locker room, aqua aerobics class and, especially, the virtual salon she presides over while soaking in one of the Rose Bowl Aquatic Center’s giant hot tubs.

“She greets me so enthusiastically every time I see her, I feel like I am one of her favorite people,” said Nancy Niebrugge, a teammate at the Aquatic Center, located south of the historic stadium, which happens to be one year younger than Kornfeld. “Then, when I was around her a little longer, I realized she is that way with everyone. You feel special around Mo.”

Growing up in Great Falls, Mont., during the Great Depression, the daughter of Maurice and Mae Kornfeld hardly could have been certain she would find a life in the big world. “Nice girls didn’t do sports,” she recalled. Young women all appeared foreordained to become teachers, secretaries or nurses.

She attended the University of Chicago and got a bachelor’s and then master’s degree in social work. She then moved to Los Angeles, where a brother, Herb, had become a painter and commercial illustrator.

In the 1970s Kornfeld managed to dodge the decade’s fitness craze and the many permutations that followed. She liked to walk and hike in the hills above Los Angeles. But when she went to the Glendale YMCA one Saturday in 1982 for a swim, she was surprised to learn the “masters” had the pool reserved.

The coach told her that if she returned she could try it out. At her first practice, coach Dom Neefe told her to swim the length of the pool and back. And she did, holding her face above water for all 50 yards, as she had learned at the old Morony Natatorium in Great Falls. “Put your face in the water!” Neefe implored. “Put your face in!” Kornfeld considered this “a bit vulgar.” But, eventually, she complied.

“And that Saturday led to another Saturday, and another Saturday and another,” she recalled. Not much later Neefe told his 60-something novice to arrive early with a $7 entry fee and he would drive her to a meet. Her tank suit, with a skirt, hardly was built for speed, but she swam the 50-yard backstroke and 50-yard freestyle. And when the meet was over, someone handed her two blue ribbons — Top Novice. Remembers Kornfeld, “I was in awe.”

In the water her arms swing a bit stiffly. She doesn’t kick as consistently as her coaches tell her to. And her reach is restricted, as you would expect for someone who has logged nearly a century on land and water.

But the swimmer makes up for imperfect form with relentless function. Her arms churn furiously, completing more than double the number of strokes per pool-length as her younger peers. And she is known for closing strong, her final laps on race days often faster than her first ones.

“She loves the feel of the water,” said Jim Montrella, a onetime assistant Olympic coach who, along with his wife, Bev, has become a mentor and dear friend. “And she is ahead of almost everyone when it comes to attitude.”

In Mesa, between heats, she huddled with companions old and new, like a swimmer from Kentucky she met a night earlier and now called her “dear friend.” Rose Bowl teammates circled and minded her, like remora fish tending to a mother shark.

The only other woman to sign up for the 95-99 age bracket dropped out. That meant Kornfeld started her races alongside octogenarians. She beat a few of the younger swimmers and won her age group in all six of her individual events — at 50, 100 and 200 yards for both freestyle and backstroke — by default. She also competed in two relays.

Last year the International Masters Swimming Hall of Fame inducted Kornfeld into its ranks. She accepted the honor in Jacksonville, Fla., but mostly shrugs off such milestones.

“Aging up is an advantageous thing, even something to look forward to,” she said, adding with a laugh, “Up to a point!”