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.

Here you can see her taking a dive into the ocean and beginning her long journey. 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.