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Ann Arbor 200

Ann Arbor's Own Mermaid: Marty Sinn

Seven hours and 39 minutes. Just shy of a standard work day. That’s how long 19-year-old Marty Sinn spent in 54 degree water in 1963. Of the initial 37 swimmers all but 10 dropped out, unable or unwilling to complete the 15 mile marathon swim in Lake Ontario. Marty’s endurance earned her international attention and a $4,000 prize as the only woman to finish and second overall.


Marty’s time as a professional swimmer was short-lived, but highly acclaimed. Prior to her icy finish in Lake Ontario she had placed fifth overall and first in the women’s field at the same race the previous year. She finished sixth in the Atlantic City Around-the-Island Swim in 1963, which looped 26 miles around Absecon Island, New Jersey. Then in 1964 she set a course record there after coming in seventh overall and first for the women. In 1963 she traveled abroad to compete in Egypt, where she finished the 25-mile Suez Canal marathon

Photo of two men in a wooden row boat in choppy waters. A second photo of a man in a wooden rowboat handing a paper cup to Marty in the water wearing a swim cap and goggles.
Marty at the Atlantic City Around-the-Island Swim, from Sports Illustrated August 24, 1964

Until Marty's arrival, the leading female long-distance swimmer was Greta Anderson. Anderson set multiple world records in marathon swimming and earned a gold medal for the 100m freestyle and silver for the 4x100m freestyle relay at the 1948 London olympics. By 1964 Marty had bested her three of the four races they competed in.

It is worth taking a moment to imagine what it means to be an open-water marathon swimmer. Contests are upwards of 15 miles in length and usually require spending at least 6 hours in the water. Swimmers’ skin turns pruny, their eyes and mouth and nose fill with water, sometimes salty, they battle currents, wake, waves, seaweed, and sea creatures. Most people would struggle just to stay afloat, let alone keep swimming in one direction while being knocked about by current. It’s easy to see why Marty was called a mermaid


Marty was raised in Ann Arbor and stayed in town to study art at the University of Michigan. Her swimming strength was cultivated during her youth spent in the all-girls Ann Arbor Swim Club and summers at Camp Ak-O-Mak. Both were run by local couple and University of Michigan graduates Rose Mary and Buck Dawson. The club was formed in 1956 after some of the camp's attendees who were taught to swim by Rose Mary expressed interest in a competitive outlet to further hone and test their skills. Its founding came 16 years before Title IX codified girl's right to participate in sports, but the demand was clear. In its first year the club consisted of around 60 girls from local middle and high schools.

Rose Mary stands between two tween girls who are holding a silver cup trophy reading "The Hardy Trophy Mich AAU"
Ann Arbor Swim Club Coach Rose Mary Dawson With Star Athletes, March 1958

Rose Mary was a champion for female athletics. In the swimming off-season she led water polo training, eventually coordinating tournaments, and revived American Athletic Union (AAU) women’s water polo. AAU was the predecessor to USA Swimming. Two years after founding the Ann Arbor Swim Club she established a women’s competitive swimming program at the University of Michigan. Then, she helped create the first women’s National Collegiate Swimming and Diving Championship held in 1962. 

In the Ann Arbor Swim Club’s first eight years, under the direction of the Dawsons, the group won six Michigan AAU team championships, placed second in the AAU nationals in 1961, and won two water polo titles. On the individual level, the Dawsons coached 17 All-Americans and 23 National Junior Champions in Ann Arbor. 

Buck and Rose Mary Dawson smiling at each other behind a table of trophies. Rose Mary is wearing a stopwatch around her neck, which Buck is holding.
Buck and Rose Mary Dawson of the Ann Arbor Elks Swim Club stand behind a few of the trophies which the local team has won.

Apart from all of its accolades, the club provided structure and opportunities for girls to understand, increase, and showcase their strength. The Dawsons left Ann Arbor in 1963 after accepting positions to coach and manage a city swim team in London, Ontario. Two of their former students continued their legacy by taking over the club after their departure. 

The Dawsons’ abundant coaching victories followed the legacy of Rose Mary’s father, Matt Mann, who founded Camp Ak-O-Mak and who was responsible for the national prominence of the University of Michigan men’s swimming team. Beginning in 1925, his nearly 30 years as coach brought the team 16 Big Ten championships and 13 national championships. Amid these wins he also coached the U.S. men’s Olympic swim team in 1952, which netted the country 9 medals. Before it was called the the Cliff Keen Arena, the University of Michigan's athletic building at 616 E Hoover Ave housed a pool from 1956 to 1988 that was named for Matt Mann. 


Marathon swimming is not a well-known sport or full of household names. Marty earned national media attention, including features in Life Magazine and Sports IllustratedBased on the coverage she received, Marty’s prominence in the media was predicated not only on her tremendous stamina, but her novelty as a female athlete. 

"Marty Sinn Swims and Swims: Sunny Mermaid of the marathon" article from Life magazine. Includes a photo of Marty leaning on a dock and a second photo of her being carried after a race.
Life Magazine feature on Marty Sinn, 1964

Nearly every article emphasized her appearance in almost equal standing with her fortitude. Sports Illustrated’s 1964 profile began, “Professional long-distance swimmers come in many shapes, but Mary Martha Sinn's is the best.” The author then tells the “legend” of her dating life – an almost certainly apocryphal tale of her 56 dates with 56 different boys in her first 56 days at college. She tried her best to deflect attention, saying, “I don't want to make my private life a spectator sport, too."

Professional sports are largely funded through sponsorships and advertising. The greater the audience, the more money the sport can earn. In 2021, NCAA rule changes allowed collegiate athletes to sign name, image, and likeness deals. For the first time collegiate athletes were qualified to earn income from endorsement deals. This change laid bare that for young, female athletes, the easiest way to attract advertisers may still be through emphasizing their appearance.

Buck Dawson seems to have recognized this. As the Executive Director of the International Swimming Hall of Fame he wrote to a fellow board member in 1971, “We are training a marathon swimmer to re-inject some glamour into the races this summer. She is a Greek girl (Greek father, American mother), beautiful, determined, and I think we finally have ourselves another Marty Sinn” [emphasis added]. This “Greek girl” was Diana Nyad, the swimmer who was the focus of the 2023 feature film Nyad.

Comparing the newest up and comer’s beauty and glamor to Marty acknowledges that, planned or not, the attention to Marty’s looks ultimately helped bring greater awareness to the sport. It was a tactic worth replicating.


Portrait of Marty Sinn, sitting, wearing a blouse and pleated skirt. With a silver trophy and a framed work of art of a nude woman sitting in a chair behind her.
Marty with a swimming trophy and her artwork

Throughout the hoopla around her success, Marty repeatedly told reporters that professional swimming was a means to an end. She told Sports Illustrated, "Swimming is just part of my life. A fifth. I have other interests." The money she earned was put toward studying abroad. By the end of 1963 she had won almost $10,000, which helped fund her art studies in Mexico City and Rome.

An article from the Ann Arbor News describes her two shared passions, “Tagging along with her swimming ambitions is a long standing and strong attraction for art which started when she was five years old. Each time she returns from a swimming meet, she brings home exquisitely rendered watercolors, oils or charcoals depicting impressions along the way.” 

When asked in 2006 about taking part in sports before the advent of Title IX the now Marty Sinn Catalano said, “being involved in the beginning stages of the larger women’s sports movement was a unique privilege… We were breaking new ground as female athletes and it was a grand adventure." Her wins helped her travel the world and expand her education.

Determined and focused despite it all, Marty stuck to her word and her career in swimming ended soon after it began. Back in 1964 she said, "I'm a little critical of people who train so intensely—they become machines instead of people, they become masochists. I just don't believe in it. It's detrimental to your character later, naturally, and to the sport, too. Obsessions can become vicious. You get so wrapped up, you lose perspective." She never let swimming define her, allowing her to continue to enjoy it as a hobby. In a 2020 podcast interview Marty said, “I love swimming. To this day I’m a lap swimmer.”

Buck and Rose Mary Dawson, Coach & Manager, Look Over Trophies Won by Ann Arbor Elks Swim Club, March 1963 Photographer: Doug Fulton

Buck and Rose Mary Dawson, Coach & Manager, Look Over Trophies Won by Ann Arbor Elks Swim Club, March 1963 image
Published In:
Ann Arbor News, March 7, 1963
SWITCHING POOLS: Buck and Rose Mary Dawson, manager and coach, respectively, of the Ann Arbor Elks Swim Club stand behind a few of the trophies which the local team has won in the eight years since the Dawsons organized the club.

Ann Arbor's Marty Sinn A Real Swim Pro

Ann Arbor's Marty Sinn A Real Swim Pro image
Parent Issue
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Ann Arbor Swim Club Coach Rose Mary Dawson With Star Athletes, March 1958 Photographer: Eck Stanger

Ann Arbor Swim Club Coach Rose Mary Dawson With Star Athletes, March 1958 image
Published In:
Ann Arbor News, March 24, 1958
THE BIG POINT: Twelve-year-old Robin Lawrence (left) and 14-year-old Janice Snavely (right) give each other the credit while their coach, Rose Mary Dawson (center), is impartially pleased with both. But a pointed question could be raised as to whether it was Miss Lawrence's or Miss Snavely's point which accounted for the Ann Arbor Swim Club's team victory, 98-97 over Detroit Turners, in the State Women's Championships. Miss Lawrence picked up a surprise point in the 200-yard back stroke while Miss Snavely gained one in the 500-yard free style. Without their two points, the 96 gained by teammates wouldn't have been enough to bring the Hardy Trophy to Ann Arbor.