Reponded to Krousman
I apparently have it wrong about where the water gets in on my paddling wetsuit. Not talking about surfing suits at all - I don’t know them. And it makes sense that a wetsuit for designed for an activity involving persistent full body immersion will be put together differently than one intended to handle more controlled or emergency only immersion.
White water is probably the wettest that anyone had in mind when designing the earlier paddling wetsuits. Which is darned wet - but I also know a lot of older white water paddlers who simply got used to being cold. And the idea that a roll is not optional for sea kayakers is a more recent thing than for WW, at least in the US it seems.
Demystifying cold challenge
It really helped me during my Wilderness First Responder medical training to BOTH learn the underying principles AND then to be put in situations and experience them, and then to discuss the physics of cold callenge and how to deal with it.
Conduction- biggest challenge to robbing us of our warmth usually, as water is 25 times more efficient in removing heat through conduction.
Drysuit works to reduce conduction as trapped non-flushed warm air is going to be 25-250 times less robbing of our heat.
Wetsuit- divers frist flush warm water into their wetsuit. Cold water entering a wetsuit requires our body to first heat it, using up our limited furnace ability to rewarm our shell body. If a wetsuit fits closely, (farmer john is only 30% as efficient as full properly fit diver wetsuit!), and it is a full 1/4" or more, it can be very efficient, but divers in frigid water wear 5-9 mm wetsuits, full ones armpits, neck, head, and they fit perfectly NOT restricting circulation!
Convection-we all know about wind chill, but some do not realize that a 5 k current or 3 foot waves make air and water remove heat about 10 times more than usual. This means water can remove heat 250 times more than air. Yikes.
This is where shells can be so helpful, why better to stay in cockpit sheltered, why best to stay home on very windy days as the cold challenge is severe and can pyramid on other cold challenge factors, i.e., increase the evaporatie rate as well.
Evaporation- this can be a dramatic and lethal addition to the other challenges for paddlers. Both wet and drysuits that have fabric outer surfaces that do not shed water quickly, either that are not smooth, and are hydrophillic, (love and keep water), or that shedding treatment has worn off, can produce severe evaporative effects. IMO chill cheaters main benefit over some other products is the smooth exterior (I have never used them so defer to others here). Mystery hoods, and drysuits that have good water treatments have much less evaporative cooling.
Radiation- although some companies tout that they have titanium and other ways to reflect back radiation effects, most scientist friends of mine say this is baloney and that there are few products out there to help with this.
I do have a product by the original space blanket people called Pro-tec Extreme, that is a 9 oz. survival bag that is three layers of mylar aluminized like a 3 in corrugated paper box construction. It is equivalent to a 20 degree 3 season sleeping bag. It reflects up to 70% of radiation, it reduces conduction and evaporation, and it is a shelter from rain and snow and wind and in the shape of a mummy bag. I recomend it highly.
fuzzy rubber hood, neoprene
for constant immersion a neoprene hood IS much better than a fuzzy rubber hood. My advocacy for it has to do with convenience in that it’s easily rolled up and kept in the pfd come hell or high water so that those transitional/benign conditions where the hood is too much and nothing is the option the fuzzy hood is available.