Hollowfill for drysuit undergarment?

[Birddog1911]

Taking my Drysuit specialty this week, and looking for options for undergarments. One thing that I do have already are a hollowfill pants and jacket. Very lightweight, great insulating properties. They'd easily crush down under a drysuit. In particular, what I have is the military Extreme Cold Weather Clothing System.

Just wondering if anyone has tried something like this, and any benefits/drawbacks. Thanks!

 

[Marie13]

I love my Fourth Element Arctic (fleece).

What is the actually filling for what you have?

 

[Birddog1911]

I love my Fourth Element Arctic (fleece).

What is the actually filling for what you have?

Marie, it's actually called hollowfill. It's sort of a high tech, synthetic down...? Stuff is amazing. In the mean time, I'll take a look at the fleece you like.

 

[Marie13]

Some drysuit undergarments are quilted type things, but I'm not sure on the actual filling. All I know is that it's not real down.

I've read that some people have issues with venting air with a Weezle undergarment (one of the sleeping bag looking type ones!).

 

[KevinNM]

How much thermal protection does that offer when soaked with seawater? One thing that actual DS undergarments do is to keep you from freezing to death when you eventually get a leak. You won't be comfortable but you won't reach the point where your hands don't work and you can't think, at least on normal dives. People do things like 5 hours of deco in 4c water, but that is something way past my experience.

 

[Birddog1911]

Kevin, if it was soaked, I'm sure that the insulation properties would go down. Marie did bring up a point I hadn't thought of; being somewhat loose, I suppose there is the possibility of it interfering with the exhaust valve.

 

[runsongas]

hollofil is older technology compared to primaloft or thinsulate. it is made out of polyester also but doesn't have the same warmth to weight ratio (due to the fiber size). while usable, you will end up using more weight and insulation to compensate.

 

[Birddog1911]

That answers my question; thanks, Runsongas.

 

[soggybadger]

Quilted materials = more lead needed as I have found. I wear a t-shirt and sweatshirt on the top half and jogging bottoms for the rest. It's the hands face and neck that feel the chill. The missus wears forth element undersuit. If you are getting your own dry suit then maybe go for the dry glove system too.

 

[stuartv]

If what you have is warm enough and the bulk doesn't restrict your mobility to an unacceptable level, no reason not to go with it for now. What water temps are you expecting in your drysuit class?

Things that could be issues:

- material could block gas going out of the exhaust, as Marie noted. But, you can wear a thin fleece or something over it, if you need to, to keep the exhaust valve from just sucking up the shell of the ECWS jacket and being blocked.

- light or medium weight Merino wool shirt, leggings, and socks are generally awesome as drysuit undergarments.

- Fourth Element Arctic gear is also awesome. It's what I use for really cold water. But, it's really warm. I have actually been thinking about getting something a little lighter (like Fourth Element Xerotherm) to use when I'm not spending a long time in the 37F water on the bottom of our local quarry. For water in the 50s and even high 40s, the Arctic stuff is more warm than I need and the bulk can be a little annoying when it's not needed.

- undies that are not made for scuba use may not have some detail features that can be nice - in particular if your pants/leggings don't have stirrups, then putting on the drysuit can possibly cause them to pull up your legs, which is annoying. Similar for long sleeves getting pulled up by the drysuit sleeves.

- on the flip side, you don't want undergarment sleeves that are too long and can't easily be pulled up. I've gotten pretty wet before from having an undergarment sleeve that was sticking down too far and interfering with my wrist seal.

- you also don't want anything with a collar that is too bulky and interferes with your neck seal.

- did I mention how awesome Merino wool is? It will keep you warm even when it's wet. And, it actually has a chemical/physical property where, when it gets wet it actually has some kind of very slight exothermic reaction which causes it to give off a little heat. It's not that getting it wet will make you feel warmer. You just won't feel AS cold as with other materials. Merino undies from REI or Amazon or wherever make great drysuit undies and are usually less expensive than scuba-specific gear.