Suit within a suit

[*Floater*]

Here's an interesting read about a bunch of divers who settled on wearing heavy duty neoprene wetsuits under their drysuits: http://www.cisatlantic.com/trimix/strike/snowyriver.htm

 

[beesonj]

Interesting read, I didn't think I was totally crazy. I'm not quite sold on wearing fabrics that wick moisture away, in this respect (although I do ususally wear synthetics). I question that because moisture won't escape the dry suit itself. I suppose there may be some benefit for the moisture to wick to the inner layer of the drysuit, but its still won't escape entirely.

Only one way to find out! :0^)

 

[jonnythan]

Cotton, when wet with sweat, offers no insulation whatsoever.

Polyester, in the form of underwear (think Under Armor and things like that) or fleece, retains most of its insulation when wet with sweat.

There will be a big difference in warmth wearing thin polyester underwear from the local sporting goods store vs cotton.

The crucial thing isn't that the sweat will *escape*, because it obviously won't. The crucial thing is that the fabric doesn't become a super-efficient heat conductor when you sweat into it. Cotton completely and readily saturates with water - polyester and other synthetic fabrics maintain air spaces by distributing the moisture throughout a large surface area on the fibers and through the garment.

The "wicking" action isn't wicking the moisture out of the drysuit, it wicks it throughout as much of the fabric as possible. A wet spot on a cotton shirt will be much smaller than a wet spot with the same amount of water in a polyester undershirt. Increasing the surface area of the liquid in such a manner is what is referred to as wicking. Incidentally, this does help the garment dry significantly faster when wet, but that side benefit obviously means nothing when underwater.

 

[spectrum]

I was on a dive boat today and a diver had a 3mm shortie he wore under a neoprene drysuit. It was an older suit and he expected a few leaks. He was very happy with his 2 40+ minute dives in 47F water. I saw him exit the suit and he didn't seem to be any moister than I was from sweating in my suit.

It's not the ultimate but in the right circumstances it can have some merit.

Pete

 

[BigBill]

Cotton, when wet with sweat, offers no insulation whatsoever.

Polyester, in the form of underwear (think Under Armor and things like that) or fleece, retains most of its insulation when wet with sweat.

There will be a big difference in warmth wearing thin polyester underwear from the local sporting goods store vs cotton.

The crucial thing isn't that the sweat will *escape*, because it obviously won't. The crucial thing is that the fabric doesn't become a super-efficient heat conductor when you sweat into it. Cotton completely and readily saturates with water - polyester and other synthetic fabrics maintain air spaces by distributing the moisture throughout a large surface area on the fibers and through the garment.

The "wicking" action isn't wicking the moisture out of the drysuit, it wicks it throughout as much of the fabric as possible. A wet spot on a cotton shirt will be much smaller than a wet spot with the same amount of water in a polyester undershirt. Increasing the surface area of the liquid in such a manner is what is referred to as wicking. Incidentally, this does help the garment dry significantly faster when wet, but that side benefit obviously means nothing when underwater.

I was thinking the same thing about using Under Armour compression shorts. Instead I purchased a pair of Speedo Jammers which are the same thing. I wanted something other than a swimsuit under a wetsuit, but not the traditional Speedo, and knew that the Under Armour works well for wicking away moisture. I am going to try out this theory this weekend using a 7mm wetsuit.

Now could you use the the same Under Armour products for your upper body, under the wetsuit?

Bill

 

[Darnold9999]

Tried something similar a few times. 1 mil shorty under a single layer of fleece in a trilam. Works like a charm - requires less lead than the one layer of fleece and a fleece jacket I would normally wear and is much warmer. Way less bulky than the two layers of fleece. With a 1 mil flexibility is pretty much a non issue as well.

Was with a diver on my last trip that tried the same thing but with a full 1 mil suit(1000+ dives). He dropped a layer of undergarment, a bunch of lead and also found it was warmer. This was not at my suggestion, he just thought he would try it.

One serious drawback. The zipper down the back means that you have to undress completely to pee. On a two tank dive that is a serious problem (for me). I think I will get a front zip 1 mil and see how that works.

If you sweat then it does have nowhere to go, but the insulation is so good that it is a non issue - again for me.

Still experimenting with this so not my final opinion, but dropping 2 - 4# and being warmer and less bulky works for me. Have not tried this on long deep dives at all - most of my diving is 60 - 100 feet so compression may be a factor that would make this a bad idea for deeper dives.

 

[jonnythan]

I was thinking the same thing about using Under Armour compression shorts. Instead I purchased a pair of Speedo Jammers which are the same thing. I wanted something other than a swimsuit under a wetsuit, but not the traditional Speedo, and knew that the Under Armour works well for wicking away moisture. I am going to try out this theory this weekend using a 7mm wetsuit.

Now could you use the the same Under Armour products for your upper body, under the wetsuit?

Bill

If you're diving wet, a layer of polypro or similar material under the wetsuit will not help, unless the wetsuit is so big that the addition of the polypro helps limit water movement in and out of the suit.

Once a fabric is completely waterlogged, it doesn't matter if it's cotton, polypropylene, nylon, wool, modal, or whatever. Completely loses any insulating qualities and wicking ceases to mean anything.