The final strokes will put her up against two familiar and formidable adversaries: fatigue and jellyfish.
Nyad, 64, on her fifth attempt to swim the 103 miles from Cuba to Florida without a protective cage or flippers, was roughly 2 miles from Key West by late morning Monday, according to her website.
This is the farthest she or anyone else has gone without a shark cage, and the wear on her body is showing. Around 7:30 a.m. ET Monday, she was slurring her speech because of a swollen tongue and lips, her support team reported on its website.
As the team called her around dawn for her first feeding since midnight, she took longer than normal to reach the support boat, the report said.