Over 100 miles of open ocean – teeming with sharks and surging with strong currents – stretch between Cuba and Florida.
In 1978, former Olympic swimmer Diana Nyad attempted the route, but failed, due to weather.
In 2011, she tried again, at age 61, to conquer the dream that has eluded her.
For two years, Nyad trained from the gym to the pool to the ocean. CNN followed her tenacious pursuit of what she called “The Xtreme Dream.”
Chief medical correspondent Dr. Sanjay Gupta has followed Nyad's two-year journey and interviews Nyad about her grit and determination to hone her body into a machine, and prove that big dreams are within reach and at any age.
CNN Presents: Diana Nyad Xtreme Dream airs on Saturday, Sept. 17, at 8:00pm ET.FULL STORY