Sting of defeat as jellyfish and storms force swimmer to end marathon effort

Her support team said she made the decision after being pulled from the water a day before her 63rd birthday.

Ms Nyad left Havana on Saturday in her third attempt since last year to be the first person to swim the Florida Straits without a shark cage. She also failed once earlier to do so with a cage.

This time she lasted longer, and made it further – swimming for more than 41 hours. But overnight was the second straight night of storms, and the crew was improvising ways to prevent hypothermia and fend off further swelling of her lips and tongue after stings.

“She realised that the obstacles against this swim were too great and agreed at dawn to return to Key West by boat,” a spokeswoman said.

Team member Vanessa Linsley said Ms Nyad encountered a triple threat of obstacles. “Instead of getting hit with one doozy they got hit with three. They got hit with the weather, they got hit with the jellyfish and they got hit with the sharks all at the same time.”

Ms Nyad was stung nine times by box jellyfish on Monday night alone.

She had been using a body suit which her team hoped would offer better protection than in previous attempts – covering her from head to toe, except for holes for the eyes, nose and mouth. But as jellyfish rose to the surface during the nights, it was clear it was not working as well as had been hoped and Ms Nyad was swimming backstroke to minimise contact.

It was jellyfish stings that forced her to cut short her second of two attempts last year as toxins built up in her system.

Ms Nyad has been training for three years for the feat. She was accompanied by a support team in boats, and a kayak-borne apparatus to help keep sharks at bay by generating a faint electric field.