Diana Nyad, positioned about two miles off Key West, Fla., Monday, Sept. 2, 2013, swims towards the completion of her 111-mile trek from Cuba to the Florida Keys. Nyad, 64, is poised to be the first swimmer to cross the Florida Straits without the security of a shark cage. The white underwater streamer, trailing from the support boat's boom, serves as a navigation aide for Nyad. (AP Photo/Florida Keys News Bureau, Andy Newman) ( Cuba-Swimming to Florida )