Swimming With Sharks, at 61

At the age of 61, Diana Nyad is taking on an athletic challenge that she could not complete in her 20s. She plans to swim about 60 hours in the churning sea, 103 miles across the Straits of Florida from Cuba to Key West.

Every hour and a half, she will stop to tread water for a few minutes as she swallows a liquid mixture of predigested protein and eats an occasional bit of banana or dollop of peanut butter. She will most likely hallucinate and endure the stings of countless jellyfish. Along the way, sea salt will swell her tongue to cartoonish proportions and rub her skin raw….

Ms. Nyad attempted this swim once before, unsuccessfully, in 1978 at the age of 28. She swam inside a shark cage for 41 hours 49 minutes until the raucous weather and powerful current pushed her far off course and she was forced to give up. She had traveled only 50 miles. (One year later, she swam 102 miles from Bimini, in the Bahamas, to Jupiter, Fla., without a shark cage. She still holds the record for the world’s longest ocean swim.)

This time, armed with better technology and a battered but tough body, she is certain she will make it. “Physically, I am much stronger than I was before, although I was faster in my 20s,” said Ms. Nyad, who looks sturdy enough to defy a linebacker. “I feel strong, powerful, and endurance-wise, I’m fit.”

To learn more about Ms. Nyad and her remarkable swim, read the full story. “Ready to Swim 103 Miles with the Sharks,” and then join the discussion below.