Yes, that's quite true. Wool is still a good insulator when wet. But that's when you're out of the water, of course, and something dry would still be better.
So ... it's best to strip down to skin if you're going to be submerged for a short time, say ten minutes, in icy water; keep your clothes as dry as possible for later changes. But if you're not completely submerged --- you're caught out in a nasty Pacific storm in January, for example --- it's best to wear wool, which, even if wet, will insulate. Cotton leaches warmth from the body, and fleece is useless.
How about some of the new synthetics ... Gor-Tex, for example?
Don't need it for this novel, but knowledge doesn't go stale ... thanks, Ramius!
I’d say so. Though, ten minutes in icy water is an eternity. :-)
On balance, while clothing does provide some insulation under water, it is more useful (maybe life and death essential) to have something dry to put on when you get out. Immediate warmth needs to be found.
Yes, there’s that old saying that “cotton kills”, and it is no joke. Cotton wicks heat away from the body faster than bare skin does.
Fleece and the other modern fabrics are a mixed bag. I don’t think fleece is much good wet-— but it does have the ability to dry fairly fast. Maybe somebody else can calibrate me on this but I think fleece can be wrung out with good success. It doesn’t hold much water. So wringing it out and putting it back on is maybe not a bad idea.
Gore-tex is a great windbreaker. Really key for staying warm. Layering, layering, layering. Standard pacific northwest outdoors apparel goes something like:
— polypropylene underwear. Good stuff. Wicks moisture away from skin.
— wool shirt.
— fleece jacket or vest. Extra insulation.
— gore-tex shell windbreaker. Lets moisture out, protects from wind. rain hood.
— Hat. Most of heat lost is from the head. Must have a hat or hoodie.