How much insulation do you wear?

[reefugee]

From my understanding, cotton has no insulation value when wet. When you are diving with a drysuit - you will sweat - which will get the cotton wet.

Ok thanks,

One more question though. I have read several times that cotton is bad to use under drysuits but no one ever mentions why?

 

[ToddK]

I'd definitely avoid cotton, as mentioned if it gets wet it really sucks. Besides sweating, your drysuit could leak a bit, or you could even just catch a little water being out on the dive boat. My PolarTec insulation isn't drysuit specific...it's left over from my backpacking days, and it seems to work just fine, and with less cost.

 

[CompuDude]

Ok thanks,

One more question though. I have read several times that cotton is bad to use under drysuits but no one ever mentions why?

There's an old mountaineering adage that says, "Cotton kills!" Cotton loses nearly all it's insulating qualities when wet. Where as fleece, thinsulate or wool will all insulate even if wet.

No cotton. You WILL sweat in a drysuit, even if you're cold. Cotton will be drenched in no time, and worse, it does not transport moisture away from your skin at all, which most technical fabrics do, so you'll be stuck with cold water leaching heat away from you and no insulation whatsoever in your fabric.

Cotton is great topside on warm days. Cotton is terrible for nearly any other circumstance.