Survive Hypothermia
Last month we discussed that hypothermia can occur in Florida when water temperatures are as warm as 80°. So, if you find yourself drifting in the water, what can you do to avoid hypothermia?

The simple answer is that you need to minimize the rate of heat loss from your body. You can do this by tucking your arms and legs close to your body with your hands in your armpits.
Maximize your buoyancy, attempting to elevate your head above the water.
Discard your dive weights as well as your SCUBA regulator and any other dense objects you have on you.
If your dive buddy is present, you may wish to assist each other in completely de-pressurizing your SCUBA cylinders to maximize positive buoyancy. An empty 80 ft.³ aluminum cylinder is about 4 pounds buoyant in seawater. If your cylinder is still negatively buoyant after depressurization, discard it.
Tighten and fully inflate your buoyancy compensator or life vest.
Lastly, if more than one person is present, do a group hug…and remain in that position. (Huddle like an Emperor Penguin during winter in Antarctica)!

Be as conspicuous as possible and hope and pray someone comes by to pick you up.
Stay Warm!

Also see: http://www.shipwrite.bc.ca/Chilling_truth.htm