A 49-year-old endurance swimmer has been given up her quest to become the first woman to swim unaided from Cuba to the Florida Keys.

FOX News Radio's Liz White has the story:

Enduring jelly fish stings, dodging hammerhead sharks...it was the fickle current that cut short Penny Palfrey's quest.  The British-born Australian athlete made it 74 miles into the 100-mile swim from Cuba to the Keys.  

Hoping to become the first woman to swim the distance without the aid of a shark cage - relying instead on equipment that surrounded her with an electrical field to keep predators at bay - 41 hours into an estimated 56-hour swim that began in calm, tepid waters, team members tweeted her crew pulled her out of the strong southeast current and onto an escort boat.

Liz White, FOX News Radio.