I'd disagree with that. Every person is different, everyones physiology is different and so on.
What one person classes as warm someone else classes as cold.
I know people that'll happily dive without gloves in 8c water for an hour with no issues whereas im in intense pain in any wet gloves after 10 mins for example.
Wearing a 200g weezle extreme, wicking base layer, 2 fleece layers, 3 pairs of hiking socks, weezle booties, dry gloves, 7mm hood im freezing after 20 mins or so. Someone else i dive with just uses a pair of arctics and is happy for much longer.
Not everyone is equal when it comes to cold.
I was calling dives in the florida keys after getting cold in a 3mm full length with hood and gloves in the middle of summer. Others were diving with no suits.
I agree with your point that individuals vary greatly in their tolerance to cold, but I'm one who gets cold more easily than almost everyone I know, and by working on some combinations and techniques, I finally got "toasty warm" on these coldwater dives.
It was a almost a matter of survival because I have the metabolism of a turtle!
....Actually, I'm colder right now sitting in my chair than after 2hrs in the 40F water a few days ago! Seriously.
I'll compromise a little and say, for
most people, in water as low as 40F (4C),
great warmth can be achieved with
full-coverage passive thermal protection, as long as it effectively traps air and not moisture and is not constricting.
Below that, it often becomes a matter of adequately protecting the hands and head and having enough room in the suit for extra insulation without creating too tight a fit that will constrict blood flow and greatly diminish the gains.
Protecting the head and face
completely is something people don't always do. An ice cap underhood is a huge benefit to me. Everything else being equal, if I don't have the ice cap covering that little bit of exposed areas of the face, I will get cold much quicker!
I think it's also very important to avoid losing core heat during the pre-dive and surface intervals and maintaining core heat by having eaten well, etc. Not news to you, I'm sure.
This also won't surprise you, but if I have a "weak link" in my setup, such as having laced my Rockboots too tight, that will cause my feet to get cold and noticeably make my core colder.
It's pretty apparent to me that any "weak link" in one's thermal protection can have very negative results.
Dave C
