Wet and dry suit?

[DivingCRNA]

I have a friend who was wearing a 5 mm wetsuit under his drysuit. He said it kept him warm.

I am asking this because I just bought a drysuit and have not gone diving in it yet. I put new seals on yesterday and am getting in the pool sometime soon.

Here is the question-Why don't more divers put a wetsuit on under the dry suit?

It gives thermal insulation when dry (god I hate wearing a 7 mm suit on land when it is hot out, but the water is cold).

It gives thermal insulation when wet (in case of a suit flood).

Most divers already own one.

Or do the undies help keep you warm while you get out of the water cursing because your drysuit flooded?

Does the wetsuit start to stink because you sweat in it without it getting flushed by the water during the dive?

Do you forget you are diving dry and accidentally pee in the wetsuit?

I understand not putting a 7 mm on under the dry suit. Most 7 mms are a b&^%$ to get on. But why not a 3 mm or a 5 mm, of a 3/5?

Thanks!

 

[Soggy]

There are several problems here.

First, wetsuits are compressible, so have variable insulation depending on depth.
Second, there is no such thing as being dry in a wetsuit.

Also, consider that while you are overheating on the (warm) surface in your wetsuit, you are sweating. Now, take that wetsuit into a 45 degree environment and you won't be so warm anymore. You have now effectively rendered the drysuit pointless, since you have sweat against your skin.

Basically, you get all the disadvantages of a wetsuit and lose all the advantages of the drysuit.

What you want is a wicking layer close to your skin to keep your skin dry, combined with an insulating fabric that maintains its insulatating properties when wet. The best fabric for that is compressed (type-B) thinsulate.

 

[spectrum]

Paragraph removed by me because it was bogus.

The HUGE problem is I see is stability. A wetsuit will only change so much with depth, it is predictable and it will rebound. If you dive down in a drysuit and it burps, tears or otherwise looses gas you are not coming home, la la la loom. You could carry a pony bottle for suit gas but now it's even more volatile and cumbersome.

Being in a wetsuit you will still perspire and that can't feel or work too well.

The bulk and lack of streamline is also a big downside.

Short answer, dont' do it. That being said I did give it a good bit of thought myself so you get an A for thinking outside of the box.

Pete

 

[kidspot]

Since the wetsuit is a closed cell material it won't rebound when air is added, only when pressure is reduced (meaning shallow ascent) it doesn't matter if the pressure is due to air or water though.

DS undergarments are "loft" materials, they do not have a gas based cell structure (like the nitrogen blown neoprene does) thus when air is added they regain their "loft" their insulation properties are based on air pockets trapped between fibers, not within the fibers.

A flooded drysuit with proper undergaments will still keep you warm ... thus NO COTTON! lol I've only had my ds leak once (after using a porous patch - bad move lol) and while it was warm water (75*) I didn't realize the suit had even leaked until I got out and poured the water out of the suit...

the advantage I've considered wearing a wetsuit underneath is that you don't have the folds in the material etc. so it fits better than most undergarments... but just not worth the disadvantages...

Aloha, Tim

 

[spectrum]

Since the wetsuit is a closed cell material it won't rebound when air is added, only when pressure is reduced (meaning shallow ascent) it doesn't matter if the pressure is due to air or water though.

You are right Tim, I hadn't though that through well enough.

Now I can say I learned something from a Hawian drysuit diver.:11:

Pete

 

[Irene]

A friend of mine was having some trouble with her drysuit leaking. After some goading, she tried wearing a 1 ml instead of undergarments...just to see if it would keep her warmer (since she was getting kind of wet anyways).

After one dive, she switched back to her thermals....said while she was warmer in the leaky spot, the squeeze with the wetsuit compression was not worth it at all. And this was on a shallow dive.

 

[HowardE]

Not only with the squeezed wetsuit would it not be effective, but I thought the thermal protection of the wetsuit is from the small amount of water that gets between your suit and your skin is warmed up. A wetsuit - dry - doesn't have the same thermal properties as a wetsuit - wet.

 

[Humuhumunukunukuapua'a]

Since the number one requirement for dysuit undies is that they wick moisture away from your skin, neoprene seems less than ideal.

 

[abitton]

Not only with the squeezed wetsuit would it not be effective, but I thought the thermal protection of the wetsuit is from the small amount of water that gets between your suit and your skin is warmed up. A wetsuit - dry - doesn't have the same thermal properties as a wetsuit - wet.

Acutally, that's not completely true. A wetsuit works by providing insulation because neoprene is basically filled with air bubbles.

A wetsuit DOES somewhat restrict water flow, hence this also contributes to reducing heat loss.

Quite a few threads on the board discuss this topic.

Mind you, who cares how, as long as it keeps you warm, right?

A.

 

[HowardE]

It doesn't keep me warm... I use a drysuit with fleece underneath