(CNN) - Vivian Stancil never thought she'd become a swimmer, much less a competitive one with a wall full of medals.
"When I was younger, for a woman of color, swim was a taboo," the 71-year-old says poolside in Riverside, California.
Stancil's hazel eyes light up when she talks about what swimming means to her. "The water is my best friend."
Her mother died when she was just 7 years old. Her father, an alcoholic who had tuberculosis, also died. Stancil, the oldest of five children, had to grow up fast. "So here I was, taking care of a set of twin sisters and two brothers until the school found out I was supposed to be in school."
The siblings were separated -- sent to different foster homes. Stancil ended up living in three foster homes. "One foster parent didn't care for me because I was too dark. I had a difficult time."
At age 19, her sight began to fail because of a rare condition called retinitis pigmentosa, an inherited disorder that breaks down cells in the retina. The National Institutes of Health estimates that the disorder affects 1 in 4,000 people worldwide.
Each year, as she got older, Stancil's eyesight got worse.
"I don't see anything today."
Weight ballooned to 319 pounds
Despite those challenges, Stancil went to college, got a bachelor's degree and ended up teaching kindergarten in California's Riverside and Long Beach school districts for more than 20 years.
When she retired, her weight started to go up. At just 5 feet tall, Stancil ballooned to 319 pounds. She didn't exercise, was depressed and had no motivation: "I was always angry at somebody."
She and her husband, Turner, would eat out often with friends. They called themselves "The Eating Club."
"We knew every restaurant in this city," Stancil recalled. "We ate everything from fried chicken, ribs -- anything that we could think of, we ate."
By age 50, Stancil's health was critical. Her blood pressure was sky-high -- 200 over 100 -- and she had diabetes. Her doctor's words stunned her into action.
"He told me at 60, I was going to die, and I didn't want to die."
She told her friends how bad things were. They suggested that she swim, because "fat floats." None of her friends knew how to swim, but they knew that Stancil's options were limited: Her 319 pounds made even walking hard.
"They didn't want me to have a heart attack from running in the L.A. Marathon."
Taking the plunge
Stancil had never swum a day in her life. She found a coach and, at 50, took the plunge.
"When I first started swim lessons, I was just crying like a kid," Stancil recalled. "The coach was yelling, 'jump in, Vivian! I'm not going to let you drown.' I said, 'the water is too deep.' He said, 'you can't see no way.' "
That insult did it. "I got mad at him and jumped in, and I've been loving it since."
She learned to count how many strokes it takes to get to the wall. She also listens to how the water sounds when it hits the plastic lane lines. It sounds different near the wall, she says.
It's 5 in the morning, the time Stancil and her coach like to train before the crowds hit the pool in Riverside.
Stancil's husband of nearly 40 years, a retired VA hospital administrator, walks her a few blocks to that pool three times a week.
Turner Stancil is pulling a wood cart full of his wife's supplies while she holds on to his arm. Inside the cart are a couple of large water bottles, a towel, a swim cap, goggles and flippers to strengthen her back kick.
From a size 24 to a size 12
Stancil knew that she had to change her eating, too. Her love for leafy green vegetables grew, and she started to cook more.
On the day CNN arrived, Stancil insisted that we eat brunch with her after the swim. She whipped up a batch of scrambled eggs mixed with broccoli, black beans, avocado and a few other veggies, with wheat toast.
"Have you ever had 'Slap Yo Mama' seasoning?" she asked the crew as she sauteed.
Stancil has lost over 100 pounds: "I'm down from a size 24 to a 12." Her blood pressure is now 114 over 76, even lower than the standard recommendation of 120 over 80.
Competing in Senior Games
As she slimmed down, she quickly became competitive, taking part in the National Senior Games qualifiers in Long Beach. In 20 years, she has won 271 medals on the local and state level, despite having had two hip replacements.
"I'm hoping to win at the national level since my hips are taken care of," the swimmer said confidently.
Stancil has made a lot of friends along the way.
"Everybody is rooting for me," she said, beaming. "My fastest swim is freestyle. I love to challenge people."
Stancil's coach, Garret Shimko of the Riverside Aquatics Association, says that "for anyone who starts at that age where Vivian is right now is incredible."
"She's always like, 'what do I need to improve?' It keeps me honest too, you know, so I'm not slacking on her, either."
Today, Stancil serves as a commissioner on two of Riverside's city boards: human relations and disabilities. She's also an ordained minister who even has a pulpit set up in her house. Next to it is a long dining table for fellowship.
She has two main goals in life: "To try and get older people to get off the couch. I don't care if you don't swim. You can walk; you can play tennis; you can play pickup ball; you can bowl -- do something in your life. And take somebody else with you."
Her second goal: to prevent adults and kids from drowning. She holds two swim clinics a year as part of her Vivian Stancil Olympian Foundation, which also helps seniors and youth participate in athletics.
"We're here for a purpose. We're not just here for ourselves. We're here to encourage one another."
Stancil points out seven people drowned in Riverside in August -- a particularly deadly month. This deeply disturbs her. Stancil's clinics focus on teaching people how to float by doing the "starfish." If you can at least float, you can survive.
An alarming new report from the US Centers for Disease Control and Prevention finds that 4,000 people drown in the United States each year. Among children ages 1 to 14, drowning is the second-leading cause of unintentional injury death after motor vehicle crashes.
Stancil demonstrates the starfish on a recent Saturday. Then, the kids try it.
The teacher, athlete and advocate looks like a kid herself as she takes to the water -- like a happy fish floating.
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