Are Drysuit Undergarments really necessary?

[CAPTAIN SINBAD]

While I understand that using cotton as the first layer is a bad idea and thinsulate is the most preferred material etc. I still do not understand if there is any real science behind expensive drysuit undergarments. For ice diving, it may make sense to buy thinsulate etc but I wanted to hear if anyone has been using regular clothing under drysuits? How bad was it?

Thanks -

Sinbad

 

[The Chairman]

I tried it once and was COLD. Modern drysuit undergarments are designed to produce LOFT. Loft=warmth.

 

[noreastDIVER84]

Cotton has no insulation properties when wet. It is a great absorber of water too, so if you sweat it goes right into the cotton.

I have a set of drysuit undergarments, and I have some fleece pants and sweatshirt, granted the fleece is warm, the drysuit undergarments are warmer and even if they get wet they are still warm.

 

[Teamcasa]

James Bond wears a Tux and seems to be warm enough..

Any under garment that would wick away moisture would work well enough I suspect.

 

[FishDiver]

While I understand that using cotton as the first layer is a bad idea and thinsulate is the most preferred material etc. I still do not understand if there is any real science behind expensive drysuit undergarments. For ice diving, it may make sense to buy thinsulate etc but I wanted to hear if anyone has been using regular clothing under drysuits? How bad was it?

Thanks -

Sinbad

I'm not quite sure what you mean by "regular clothing." I use layers of general purpose fleece from Cabela's. Cheaper than specialized stuff and it works topside, too. I like thick wool socks best of all the alternatives I've tried.

 

[ZzzKing]

Patagonia 4wt combined with fleece is good for me down to the low 50's. Below that I use the 4wt under a Bare undergarment. I forgot what number it is though. The 4 wt is good by itself down to the mid 60's.

 

[netmage]

While I understand that using cotton as the first layer is a bad idea and thinsulate is the most preferred material etc. I still do not understand if there is any real science behind expensive drysuit undergarments. For ice diving, it may make sense to buy thinsulate etc but I wanted to hear if anyone has been using regular clothing under drysuits? How bad was it?

Thanks -

Sinbad

A few folks here use UnderArmour ColdGear and Cabelas ECWS...

 

[fstbttms]

I still do not understand if there is any real science behind expensive drysuit undergarments.

Try a cold water dive with cotton on underneath. You'll come a good understanding before too long.

 

[rongoodman]

One thing the Thinsulate garments are designed to do is retain their warmth while wet. Facing a deco obligation with a flooded dry suit is going to be pretty uncomfortable in pile, no matter how warm it might be when dry.

 

[tbone1004]

I wrote a fairly hefty argument against most drysuit undergarments a month or so ago, as a textile engineer who works with this type of stuff, you've gotta think about materials. The problem with a lot of them is they don't account for where the loft is useful and where it isn't. You can make yourself look like the michelin man, but your arms won't ever get any air, and your legs don't have much at all. Drysuit squeeze. So your best bet, is to get REI polartec underwear, which is WARM. Costs $60 for top and bottom, instead of the $600 from DUI. SAME material. Then if you're still cold, you can put any real fleece material on there, and if you want loft you can put a lofty down vest or something, but putting all the lofting stuff around your arms is pointless and makes it hard to move, and same with your legs. Keep your core warm and it'll work wonders.
A down vest or the lofty stuff provides almost 0 insulation when it's compacted, so it doesn't do you any good in a suit squeeze situation. That's why the 4th element stuff is getting real popular, it works almost as well as the huge loft stuff, still works well when wet, and doesn't require a lot of air. I've got the REI polartec, which is the same stuff as their Xerotherm base layer, and I'm good for 90minute dives in 40* water. Add a thicker polartec fleece on top of that, and I'm sweating in the beginning of the dive, but the polartec wicks it away so I stay dry