Veteran long-distance swimmer Diana Nyad was plucked from the Florida Straits on Tuesday after giving up on her fourth and likely final attempt to make the 103-mile (166-kilometre) swim from Cuba to the United States.

The 62-year-old American, who battled squalls, rough seas and jellyfish, had set out from Cuba on Saturday. Nyad spent more than 60 hours in the water before she abandoned the swim.

Mark Sollinger, a leader of the crew and support team accompanying Nyad in five boats as she made the attempted crossing, told CNN a powerful and "extremely difficult Gulf Stream" had pushed her badly off course.

She had planned to land somewhere in the Florida Keys on Tuesday, a day ahead of her 63rd birthday on Wednesday. But it would have taken her another 28 to 40 hours to complete the crossing at the time she finally gave up, Sollinger said.

He said Nyad's lips and face were very swollen and she was suffering from exhaustion. Otherwise, he said, she was doing well for "someone who just spent 63 hours attempting something monumental and extremely dangerous."

He did not give the exact time when Nyad was pulled from the water or pinpoint the location, but those details were expected to be announced later.

If Nyad had completed the swim, she would have owned the world record for the longest "unassisted open ocean swim," which means without a shark cage. Instead of a cage, equipment emitting a mild electric current in the water kept sharks at bay during most of her swim.

THE DREAM

Nyad told reporters in Havana last week that she hoped her swim would inspire people her age to continue pursuing their dreams.

"Instead of staying on the couch for a lifetime and letting this precious time go by, why not be bold, be fiercely bold and go out and chase your dreams?" said Nyad, who left competitive swimming 30 years ago and has since worked in television and radio and has been a motivational speaker.

She also hoped the swim would help U.S.-Cuba relations, which have been sour since the Caribbean island's 1959 revolution.

The Cuba-U.S. swim has only been completed once. Australian Susan Maroney was 22 and used a shark cage when she made the crossing in May 1997.

Nyad has now tried to make the swim four times, including twice last year, but never got much more than halfway before she had to give up.

Asked before this latest attempt if it would be her last, Nyad said: "This has to be it, it just has to be."

Waves and stiff winds derailed her first try in 1978, when she was at the peak of her swimming career. Three years before that she swam around Manhattan in under eight hours and, in 1979, she made the 102.5-mile crossing (165-km) from Bimini to Florida.

Nyad's latest swim followed that of Penny Palfrey, a British-born 49-year-old grandmother from Australia, who tried the Cuba-Florida crossing in late June and swam 93 miles before the Gulf Stream forced her to stop.

Palfrey holds the record for the longest unassisted swim, 67.5 miles in the Cayman Islands last summer.