Swimmer to cross shark-filled Florida Straits

AMERICAN endurance swimmer Diana Nyad has begun her attempt to become the first person to swim the shark-filled Florida Straits without the aid of a safety cage.

In calm seas, the 61-year-old stroked north into the Florida Straits in her bid to set a new world record with a 165km crossing from Cuba to Key West in Florida.

The gruelling swim was expected to last about 60 hours.