Havana, Cuba (CNN) - A 49-year-old Australian woman is taking on a huge challenge.
Penny Palfrey wants to swim from Havana, Cuba, to the Florida Keys.
Not only that, but she wants to do it without the protection of a wetsuit, flippers, or a shark cage.
She is attempting to surpass a record that she set in 2011 for the longest unassisted swim.
Palfrey will be shadowed by a crew of 15 people including medical personnel.
She told CNN she's both excited and nervous for the swim, which could take anywhere from 40 to 60 hours.