Her goal, the Florida Keys, lay a little more than 100 miles (160 kilometers) to the northeast. The sea off Havana was flat and glassy, precisely the ideal conditions that McCardel's science team ...

The biopic chronicles the life of long-distance swimmer Diana Nyad, who swam from Cuba to Miami at the age of 64. NPR's Michel Martin talks to Nyad director Elizabeth Chai Vasarhelyi.