Dry Suit Question

[pdelannoy]

Has anyone wore a 7mm wet suit under their dry suit instead of using an undergarment? I am asking about this because in the multilevel diving I do at my local lake the depth changes significantly during the dive-the dive profile is not anywhere close to horizontal. I was thinking that my 7mm might work better because of its resistance to compression and its significant insulation qualities. Just wondering?

PD

 

[charlesg3]

I don't have that many drysuit dives but from my perspective it doesn't seem like the best idea. For one I find the drysuit to be more of a hindrance to range of motion than a wetsuit. Adding a wetsuit underneath would only make things worse. Also, can simply add more air to the drysuit as the air compresses at depth.

 

[fppf]

You would not want to wear a wet suit under a dry suit.

Neoprene is a closed cell material, meaning the air pockets inside are sealed. So it WILL compress as you descend, just as it does when your wear it in the water. As it compresses it will loose much of its insulation value, just as it does in water.

Fabrics are open celled insulators, fleece, thinsulate, polartech. The air pockets are open so they don't compress with depth. This allows them to maintain there insulation values at depth, this is why we need to add air to the suit. They do loose a little at depth because the higher density air conducts heat better, but not that much.

 

[RU4SKUBA]

Yeah, you wouldn't want to wear the wetsuit under the drysuit... not a good idea. But you don't have to buy a $350 polartech immediately either. There is some nice clothing available for hiking you can layer, that breathes, and is significantly less expense but still works.

Later when you have the dough, splurge on a good liner made for diving.

 

[RJP]

Has anyone wore a 7mm wet suit under their dry suit instead of using an undergarment? I am asking about this because in the multilevel diving I do at my local lake the depth changes significantly during the dive-the dive profile is not anywhere close to horizontal. I was thinking that my 7mm might work better because of its resistance to compression and its significant insulation qualities. Just wondering?

PD

Bad idea on several levels, as outlined above.

 

[AfterDark]

You want wicking poly touching your skin to keep you dry as you sweat. Cotton to absorb the moisture that is wicked from your skin and thinsulate or wool on top to keep you warm. Try putting on a wetsuit this winter if you live in a cold place and go outside for awhile.

 

[DCBC]

Has anyone wore a 7mm wet suit under their dry suit instead of using an undergarment?

This wouldn't be a good idea. You would have an excellent chance of overheating.

The body temperature rises because muscles generate about 20 times more heat when you are active than when you are at rest. The more active you are, the more water you lose. Urination would also be a bit of a problem (lets not go there).

When a diver's dehydrated his muscle tissues receive less blood flow; which affects the ability to release nitrogen. This increases the chance of DCS.

If the water (lost through sweat) isn't replaced, the body temperature goes up. If this becomes extreme, then you could suffer from heat stroke.

Like I said, not a good isea.

 

[FishDiver]

You would not want to wear a wet suit under a dry suit.

Neoprene is a closed cell material, meaning the air pockets inside are sealed. So it WILL compress as you descend, just as it does when your wear it in the water. As it compresses it will loose much of its insulation value, just as it does in water.

Fabrics are open celled insulators, fleece, thinsulate, polartech. The air pockets are open so they don't compress with depth. This allows them to maintain there insulation values at depth, this is why we need to add air to the suit. They do loose a little at depth because the higher density air conducts heat better, but not that much.

I began an almost identical post when I bought my drysuit several years ago. I received a number of answers well summarized by the cogent response above. It is a bit weird to wrap your head around, but a wet suit will compress at depth whether worn by itself or inside a drysuit.

 

[pdelannoy]

I understand that wet suits compress. But open cell insulators work by creating a dead air space which is loft. These materials compress as well under the shell. Even with an air pocket there is some compression and this results in a decrease in thermal protection. I asked the question because a wet suit will resist the compression better than thinsulate. So far, I have found that the air pocket is not uniform throughout and so my shoulders and upper chest area is warm but as you move down my lower body is cool. This was more of a brainstorming question than anything else.

PD

 

[MSilvia]

I think you'll find that closed cell neoprene will compress a lot more at depth than any undergarment I'm aware of... unless it's suit squeeze that's causing the compression.