canuckton,
Scuba Barbie did pretty good. Another thing also happens. In areas which are keratinized, part of the swelling of the tissues is due to water sorption into the overlying keratin. You have keratin all over the surface of you skin. It's thicker in areas of callous and thinner on your lips. The reason your hands turn whiter is because the keratin has absorbed the water. Certain types of skin do not have keratin--the mucous membranes of the mouth and some parts of the genitals, the lining of the esophagus, stomach and intestines. Ducts, leading to the surface of the skin, and other ducts within the body also do not normally have keratin--if they do, you got potentially serious troubles.
Now, why would anyone want to be in water for 60 hours?
If it's a stunt in a pool and you can keep your head above water easily, then I would imagine hypothermia is your biggest problem. In the ocean, however, the salt creates a hypertonic solution. Water from within your body tends to diffuse out toward the salt water. Your lips will start to shrivel and burn from the salt and your throat will get sore. Your eyes, if not protected will also be affected and will become sore-painful. If you're exposed to the sun you have the additional problem of sunburn on exposed areas and this compounds the problems. Swallowing salt water may cause the "runs". Without exposure protection, hypothermia will be a problem. Even a wetsuit for 60 hours probably won't be good protection from the cold.
Outdoor freshwater exposure can also be a problem--again from hypothermia, sun exposure, etc.
If you on a sailboard, jet ski or are doing excercise, hypothermia may be less of a problem. Then there is the matter of eating, drinking and exposure to the elements. A member of the Spanish Monachy just finished a trans-Atlantic crossing on a jet ski. I believe it took 100 days. He never got off the jet ski but support boats were present for food water and fuel.
Maybe some of the docs will respond.
Why on earth, would someone want to be in the water for 60 hours?!!!...although, I can't get my son out of the shower for nearly that long!