Dave,

I just wanted to add a follow-up to your post on the drysuits. As you noted, the function of the drysuit is simply to keep the insulation dry. It is the insulating layers that you wear inside the drysuit that provide the warmth. Wearing a drysuit alone offers little thermal protection. This was tragically pointed out a few years ago on the New Jersey coast when a kayaker capsized in cold, winter waters only a few hundred yards from shore. He was wearing a drysuit, but nothing underneath. Onlookers at the beach could do nothing to help the man. The cold water quickly overcame the paddler and he drowned before help could arrive.

As for breathability, Goretex drysuits have been on the market for several years (at a premium price). While I have not used one, I'm told by those that do that they love them. (Personally, I've had a hard time with the idea of forking over $600 - $900 for the Goretex suit.)