Marathon swimmer Diana Nyad shows the welts on her arm at Key West, Fla., Sunday, Sept. 25, 2011. Nyad spent more than 40 hours in the shark-filled waters between Cuba and the Florida Keys, climbing into a boat only to be treated for searing welts left by Portuguese man o' war stings. Left swollen and red, Nyad had no choice but to end her trek early when medics warned another sting could be deadly. (AP Photo/Alan Diaz)
Read the article: Nyad: Quitting Cuba-Fla. swim was a 'bitter pill'