Wetsuit under dry suit?

[oxyhacker]

This is an old scuba myth. Water in a wetsuit is a necessary evil, tolerated since it makes the suit much easier to construct and to use. But the water isn't what keeps you warm.

Water is a very efficient conductor of heat, not an insulator. The reason the water warms up is not because it has any insulating value, but because the neoprene, which is doing the actual insulating, is slowing down the heat transfer rate between the water inside the suit and the water outside so your body can warm the inside water faster than the water outside the neoprene can cool it. So the water inside eventually gets warmer, and you don't feel so cold as much. But the water isn't keeping you warm - you are keeping it warm! You would be even warmer if that water wasn't there since you have to waste body heat to warm it up, it up so it still represents a net heat loss.

If this was not true, why would wetsuit makers use thicker neoprene for colder-water suits, instead of fitting them looser so they would hold more water?

The neoprene itself doesn't keep you warm. It's the water that is trapped between your body and the neoprene that is heated by YOU that keeps you from freezing to death sooner than you would without the wet suit. So, a DRY suit would be DRY and that water that your body heats when using a wet suit wouldn't exist in a dry environment. Would you use neoprene to keep you warm instead of your fleece jacket in the middle of a snow storm? I hope not. Make sense? I'm sure someone else will do a better job of explaining this. I tried. LOL.

 

[Humuhumunukunukuapua'a]

The thicker neoprene keeps the colder water on the outside of the wet suit from cooling that trapped water sooner. A well fitting wet suit, regardless of thickness, should be pretty tight or it can't do its job.

It really is all about keeping that trapped water from cooling longer. Your body heats that trapped water and thus your body does cool in the process, but because of the wet suit, that trapped water stays warmer longer and is warmer than the ocean on the outside. Your body temp would sooner equal the ocean temp without a wet suit to keep a layer of trapped water inside your suit warmer.

Uh...right...and how does the neoprene keep the water (and you) from cooling? Because it's a very good insulator.

I'm sorry, but you really are being very misleading as far as how a wetsuit keeps a diver warm. It is the neoprene that insulates. The water in the suit has nothing to do with the insulation, and should be minimized in order to remain warm.

 

[JeffG]

The thicker neoprene keeps the colder water on the outside of the wet suit from cooling that trapped water sooner. A well fitting wet suit, regardless of thickness, should be pretty tight or it can't do its job.

It really is all about keeping that trapped water from cooling longer. Your body heats that trapped water and thus your body does cool in the process, but because of the wet suit, that trapped water stays warmer longer and is warmer than the ocean on the outside. Your body temp would sooner equal the ocean temp without a wet suit to keep a layer of trapped water inside your suit warmer.

The air bubbles in the neoprene is what is keeping you warm. The thicker the wetsuit, means more bubbles...more air. Thats also why when you descend wetsuits loose their thermal protection (the bubbles get compressed)

Heating water with your body steals heat from your body. Keeping this down to a minimum helps keep you warmer. Hence, why the idea of a semi-dry wet suit is warmer than a "wet suit"...also why having the correct fitting wetsuit is important. It lowers the chance of allowing water in or out.

 

[tangfish]

Putting together my first dry suit and I was just wondering-heard it mentioned in another thread.

Just use some old ski clothes, fleece, etc.

 

[scubadobadoo]

Amazing....

What do you think happens to the wetsuit when you descend?
What is done to counteract this with traditional undergarments?
Could this method be used with wetsuit undergarment method?

The wet wet suit will still compress at depth anyway if used inside or out of a dry suit. When adding air to the dry suit, even when wearing a wet suit under it, the added air will keep the suit from squeezing you to death. Compression is a non issue here. Warmth however is. A WET suit doesn't keep you warm in a DRY suit.

 

[wardric]

This is a really typical misconception, and it's entirely untrue. It is most definitely the neoprene that keeps you warm. The water inside the suit is not the insulator, because it, like all water, sucks heat away from you very quickly.

The idea of any wetsuit is to minimize the amount of water that enters the suit so that heat is not lost through convection.

If the neoprene doesn't keep you warm, then why do I wear 12 mils of neoprene over my torso here in California? I don't think a 3 mil would cut it, despite the water in the suit warming.

While I wouldn't personally use neoprene to stay warm in a snow storm, it would be effective at it. Neoprene will warm you up without being wet. Anyone who says otherwise has never worn a wetsuit.

I would think a wetsuit under a drysuit would be effective thermal protection...it's absurd to say that it has no insulative abilities because it is dry. And wouldn't the wetsuit remain uncompressed inside the drysuit? So it would not lose its insulative abilities at depth, the key disadvantage to wetsuits alone as I see it.

But as for wetsuits under drysuits, I have no experience with that, but in theory it seems like it would work. I imagine regular undergarments would be a lot more comfortable.

Nope, the wetsuit would compress as much in the drysuit as out of it. The dry is not a submarine.

When I ice dived in a wetsuit, I would freeze (especially my feet) at the surface and as soon as I got in the water (and water penetrated my suit), I felt much warmer. So I still think water has something to do with the insulation. Maybe I'm wrong, but those ice dives makes me think so.

 

[Humuhumunukunukuapua'a]

The wet wet suit will still compress at depth anyway if used inside or out of a dry suit. When adding air to the dry suit, even when wearing a wet suit under it, the added air will keep the suit from squeezing you to death. Compression is a non issue here. Warmth however is. A WET suit doesn't keep you warm in a DRY suit.

You're really really wrong. A wetsuit CAN keep you warm if it's dry. Have you ever put on a wetsuit?? I'm usually sweating like mad by the time I get geared up (before I get in the water). It's because the neoprene is a good insulator.

It will lose insulation as it compresses at depth just like any wetsuit or neoprene drysuit, but it's absurd to say a wetsuit has no insulation if it is dry...

 

[Humuhumunukunukuapua'a]

Nope, the wetsuit would compress as much in the drysuit as out of it. The dry is not a submarine.

Of course you are right. I got to thinking about it, and as you add air to the suit, you are equalizing the pressure in the suit with the water pressure. So, the suit will compress. I had a bit of a "duh" moment

So I still think water has something to do with the insulation. Maybe I'm wrong, but those ice dives makes me think so.

Sorry, you are mistaken. There's no way the 32 degree water in your suit could contribute to anything other than heat loss. It's just a fact. The water gets heat froim your body (so your body has less heat). Water is a terrible insulator. So, the water in a wetsuit has zero, nothing, zilch to do with its ability to insulate you.

 

[mongoose]

Doesn't seem to be much of a concensus on this topic today.

I can tell you I certainly don't know, but I've wondered about it. I know if I sit around the house in a 3mil (I do that sometimes) I get hotter than Tucson in August. I also get hot when I watch old CNN footage of Margaret Thatcher(those eyes!), but that's another topic.

Hell, why not just try it next time you're out at the lake? Grab some supportive and understanding friends, and hop in...What's the worst that could happen? Bouyancy issues? Grab the downline. Too cold? Get out and watch a tape of Ol' Thatchie. Alien Abduction? Grab the table and try to think of something besides the sizzling sound(that's what I do, anyway).

So, there you go.. the seasoned advice, handed down from on high by the wizened old man that picks up his voicemails from God on a daily basis:

Try it safely and see what happens.

Take care, bro.
--'Goose

 

[wardric]

Sorry, you are mistaken. There's no way the 32 degree water in your suit could contribute to anything other than heat loss. It's just a fact. The water gets heat froim your body (so your body has less heat). Water is a terrible insulator. So, the water in a wetsuit has zero, nothing, zilch to do with its ability to insulate you.

Yeah, I guess that is logical. The fact is, of course a wetsuit is warm by itself. I had (before I had a dry) to wear one even in July cause the water temp doesn't get much higher than 45 under the thermocline here, and man how I sweated under it. semi-drys are warmer (less water movement) and neoprene drys are the warmest (no water, ideally :05: ) and you can wear them sometimes with almost nothing under them (the air and neoprene do the job).

So why the H... did I feel warmer with water in my boots than at the surface during all those ice dives:06: :06: :06: