[LeifCarrotson]

Swimming continuously.

It's one thing to sit neutrally bouyant in a Scuba suit, or in a flotation device, with nothing but shivering to keep warm. Asleep, you can get hypothermia in water that is nearly at body temperature.

However, endurance athletes (like this 2.5-day-swimmer apparently decided he was) can keep warm by exertion. Competitive swimmers will keep warm, and actually sweat a great deal, in a very cold pool throughout an hour or two of practice in nothing but a speedo.

The problem only comes when one discovers, like the protagonist of Jack London's "To Build A Fire", that you lack the endurance.

[rrhyne]

He wouldn’t/couldn’t have swam continuously for 72 hours. He would have floated, treaded water, etc. the wetsuit kept him warm.

[lobf]

Did anybody read the article?? One of the most important factors was staying in the fetal position- he even lost consciousness at times and was saved by a floatation device that kept his head above water.

[agumonkey]

heat production by effort is large, probably way more efficient than shivering so your chances are probably better if you can reach a destination by swimming.