62-year-old Diana Nyad jumped in the waters near Havana on Saturday in her fourth bid to make the record-making crossing, to swim from Cuba to the USA without a shark cage. She has already been stung by jellyfish a couple of times, but is still swimming according to her Twitter stream. Read for instance USA Today

In June, Australian endurance swimmer Penny Palfrey made it 79 miles toward Florida before throwing in the towel in the face of strong currents.
A fiercely driven competitor, Nyad acknowledged it was hard to watch Palfrey come close to snatching away her long-held goal.
“If she had succeeded I would have congratulated her, because I know how difficult it is, more than anybody. And after all, this is not my ocean,” Nyad said. “But it is my dream. … Frankly — how can I lie? — I’m glad that I still have the chance to be first.”