Drysuit weight vs. undergarments?

[sschlesi]

Random winter underwear is a bad idea. Carefully chosen winter underwear is just as good, maybe better than a dedicated undergarment. I particularly like that my winter underwear is multipurpose, I already have plenty of diving specific equipment.

I'll describe the layers I wear. I find that I wear more underwear than most people I dive with. Water temps in my area are typically 38F-48F and occasionally go a couple degrees on either side of that. This system evolved over time, when I first started diving dry I found I didn't need much insulation compared to my buddies. As I improved my buoyancy skills, my SAC went rapidly down, along with my temperature, and I gradually added several layers. I don't expect I'll ever need to add more layers. I wear this with a trilam suit and dry gloves.

Layers start on the skin and work outward. Tight means form fitting, not circulation restricting.

Feet -
2 pairs heavy wool socks.

Legs -
1 thin, tight pair of wicking poly long johns.
1 heavy pair of wicking poly long johns.
1 heavy pair of fleece pants.
1 thin pair of winter runners pants (breathable, not those plasticky looking track pants)

Upper Body -
1 thin, tight long sleeve wicking poly shirt
1 medium, long sleeve wicking poly shirt
1 heavy wicking long sleeve poly shirt
1 heavy wicking poly vest
1 medium long sleeve acrylic shirt

Hands -
1 medium wicking poly glove (~2-3mm)
1 light elastic wicking poly glove (~1-1.5mm) the elastic contains the bulk of the inner glove to ease donning of the dry glove

I really like this system, and it keeps me warm. The only downside is that it is a lot of individual pieces and takes a bit of time to put on. Gradually I have learned how to put this on more quickly. Except at the height of summer I typically wear the base layers to the dive site, and in winter I wear everything to nearby dive sites.

 

[spectrum]

Random winter underwear is a bad idea. Carefully chosen winter underwear is just as good, maybe better than a dedicated undergarment. I particularly like that my winter underwear is multipurpose, I already have plenty of diving specific equipment.

I like your approach. It's not like were talking about life support here.

Pete

 

[sschlesi]

I like your approach. It's not like were talking about life support here.

Pete

That brings up another point that I forgot. It's really nice (critical in a deco situation) that your undergarments keep you warm when wet. While evolving this system I had 3 or 4 major leaks caused by a collar on a fleece jacket that didn't fit under my neck seal properly. Those dives were certainly colder than dry dives, but not cold enough to cause shivering. I have also had a couple smaller leaks that I didn't notice until I was removing my suit.

 

[DaleC]

28lb's of lead with my summer undergarments and twin Al 80's. 32lb's with my winter undergarments.

In summer I wear 20 year old wool/lycra cycling tights (the crotch is showing its age), a wicking T shirt and an old navy acryllic sweater (the one in my avatar). In winter (at some point) I usually switch to a warmer Bare polar fleece one piece suit. I agree there need be nothing "special" about diving undergarments per se as long as the rules are the same as for most extreme winter activities (primarily wicking and retaining warmth while wet). If the material passes those criterion then air trapping and flexability can be refined.

 

[jhupka]

I dive dry with the 4th element and the only weight is the gear, a steel 119, and the 6 pound back plate.....makes me wonder how weird I am seeing all these people needing 20 to 30 pounds to be down

 

[AfterDark]

Definitely ditch the cotton.

Nothing wrong with cotton over wicking poly, the moisture needs to be absorbed, cotton works for that.

 

[noreastDIVER84]

I have only 3 dives in my Drysuit (Pinnacle Evolution 2) and I am using the Fourth element undergarments. I have a AL80 and normally use about 24-26 pounds of lead with my 5mil Instadry suit, but only had to use 30 pounds with the drysuit. I was told that the undergarments for the drysuit are neutrally buoyant and will help on keeping the weighting down, but that is only what I am told.

I am going diving on Friday and will be in a bit warmer water and am just going to wear a nylon and polyester windsuit underneath and see what happens. I know it isnt going to be as warm, but I bought the drysuit for diving Dutch Springs a couple weeks ago and was down to 40 degree water there. I will only be down to 65 degree water here on Friday.

 

[dave4868]

Nothing wrong with cotton over wicking poly, the moisture needs to be absorbed, cotton works for that.

From what I've seen, much of the body-generated water vapor condenses on the colder materials, like the drysuit material and outer surface of the undergarment.

I'm not concerned if the moisture is absorbed or not; I just want it as far from my skin as possible. Droplets on the inside of the suit or outside of the undergarment are fine with me....

A cotton layer in any location will just become damp, transfer heat more quickly and also reduce breathability. It's not useful unless you're trying to prevent overheating, IMHO.

I'm even thinking of using polypropylene fleece to replace my cotton shorts that always get quite damp and cool.... not to mention quite embarrassing later if they're a dark material.....

Dave C

 

[sschlesi]

I was told that the undergarments for the drysuit are neutrally buoyant and will help on keeping the weighting down, but that is only what I am told.

I'm pretty sure that garment is not neutral, if it were it would be just as heavy as a bucket of water the size of the squished garment. Also undergarments provide most of their insulation by trapping air, all that trapped air is a long way from neutral.

I'm surprised you needed so little extra weight, but if it works, it works. Be sure to do a buoyancy check with a nearly empty tank, that is when too little weight is going to become a problem.

 

[Uraluni]

A cotton layer in any location will just become damp, transfer heat more quickly and also reduce breathability. It's not useful unless you're trying to prevent overheating, IMHO.

I was just going to mention that...a moist cotton will not breath...yes, it will absorb the moisture from your wick, but the water won't go any further than that once it's saturated and the wick effect will become useless if you don't allow that water vapor to go anywhere.