She swam so much and so fast that she broke numerous records including the 50-year-old mark for circling Manhattan island.
In case your wondering she swam around the island (7 hrs, 57 min) in 1975.
But perhaps her most famous (if unsuccessful) swim was when she tried twice to swim the 103-miles from Florida to Cuba.
Both times she did not make it and almost died trying to overcome the current, waves and sharks.
And now the 60-year-old marathon swimmer intends to try it again.
According to a recent interview in CNN.com Nyad said:
"It's daunting, I will admit to you that I'm scared to death," Diana said, in a rare moment of self-doubt, "but in other ways, I'm very confident." She continues, "I've left no stone unturned in training, I follow that oil spill every single minute, I look at the weather, I look at my team, I look at shark devices, so I'm ready."
And speaking of sharks Nyad plans to swim without a shark cage this time relying instead on an electronic device to keep the sharks away from her.
"Look at 60-year-olds today. They're not old, and I'm not old. I'm older than I was, yes. I'm slower than I was, but I'm still vital and I'm still powerful, and when I walk up on that shore in Florida, I want millions of those AARP sisters and brothers to look at me and say 'I'm going to go write that novel I thought it was too late to do. I'm going to go work in Africa on that farm that those people need help at. I'm going to adopt a child. It's not too late, I can still live my dreams."
Nyad intend to attempt the crossing to Cuba in August.
No word on if she plans on getting a waterproof Visa and or exception to visit the still Communist country.