Wet suits and dry suits

[Storker]

Sometimes, the advice to "add just enough air to prevent you from feeling uncomfortably squeezed" leaves you feeling uncomfortably cold. Even with thicker undergarments, I sometimes feel cold before I feel squeezed.

Quite.

And that's why I loathe those "don't use your DS as a BCD" warriors. Find the right balance for you, at the conditions you're diving and forget the strict rules.

 

[undrwater]

Quite.

And that's why I loathe those "don't use your DS as a BCD" warriors. Find the right balance for you, at the conditions you're diving and forget the strict rules.

I agree, but I started with "just enough to remove squeeze", and it worked while I was reducing the task load. Now I can increase the amount of air in the suit so I feel comfortable.

 

[stuartv]

Undergarments matter..

Yes! For undies to work, they need enough air in the suit to let the undies achieve their optimal loft.

Thus, it seems to me that if you use "poofy" undies, you will have to put more air in, to let them get fully lofted and provide the warmth you need. And that will result in a bubble that is harder to manage.

OTOH, if you use a "denser" type of undie, you can use a lot less air to let them loft. You can achieve the same warmth with a lot less air in the suit.

That is why I especially like my Fourth Element Arctic undies. They are very warm while being fairly dense. It doesn't take much more air, at all, to let them do their thing than it does just to take the squeeze off. I have seen other undies that look more like a suit stuffed with goose down. Goose down is great insulation in a sleeping bag. I don't want it in my drysuit.

 

[Lorenzoid]

So how does that work? I mean, a garment is either dense or it's poofy. (Where's @tbone1004 -- I need some textile vocabulary.) A dense garment can't hold as much air as a poofy ("lofty"?) garment. What am I missing here?

Yeah, my jumpsuit is quilted and feels like a sleeping bag.

 

[stuartv]

For those of you experienced with both. Would you please speak to the differences in managing bouyancy between a thick (7mm of greater) and a dry suit? Does dealing with suit crush equate to the bubble management involved in a dry suit?

I usually dive dry in the local quarry, but sometimes go with my 7mm wetsuit.

The wetsuit never, ever gives me the sensation that if I tip a little more forward, I'm going to have air rush into my feet and drag me to the surface. Managing the drysuit, so that that doesn't happen, is not hard, but it IS a difference. To me, diving a wetsuit, even a 7mm, is easier. But the difference is very small and would not sway me to dive wet. Maybe I'm just not very sensitive, but I have never noticed any extra difficulty in controlling my buoyancy when wearing a 7mm. Nowadays, I only wear the 7mm when I have a reason (e.g. working with an OW class, where it's deemed important to be in gear like what the students are using, or if it's a really hot day out and I don't want to flood my drysuit with sweat before I even get in the water).

 

[stuartv]

So how does that work? I mean, a garment is either dense or it's poofy. (Where's @tbone1004 -- I need some textile vocabulary.) A dense garment can't hold as much air as a poofy ("lofty"?) garment. What am I missing here?

Yeah, my jumpsuit is quilted and feels like a sleeping bag.

I don't know. I reckon you tagged the right person. But, if it was as simple as just having the air there, you could just inflate your suit and wear no undies at all, right? Some dense but thin-ish coats are just as warm as some poofy down coats, right?

I don't know.

 

[tbone1004]

So how does that work? I mean, a garment is either dense or it's poofy. (Where's @tbone1004 -- I need some textile vocabulary.) A dense garment can't hold as much air as a poofy ("lofty"?) garment. What am I missing here?

Yeah, my jumpsuit is quilted and feels like a sleeping bag.

sorry, thread seemed derailed so I didn't pop in. Thank God @The Chairman put a tagging feature in for stuff like this. I usually start ignoring threads after the third page or so unless I get tagged

Ok, so air is what we are using to insulate. Without using active materials like phase change materials that can heat/cool under certain conditions, we are using passive insulation to create an air barrier between the water and our skin.

The ideal solution is something pillowy because that has lots of air and will insulate very well. Downside of this is there is basically no resiliency to this kind of solution. I.e. it doesn't "spring" back when put under pressure, and it has no ability to insulate when compressed.

Next solution is to take something really resilient and make it lofty. Felts are typically how this is done i.e. things like polartec.

so, what happens here is that when the pressure from your suit goes against the fabric, the dense felt compresses less and ends up holding more air than the light pillowy fabric and gives you an extra barrier against the cold. This can be made better by things like hollow fibers *DuPont's Thermax* which holds some more air.

You want more insulation around your chest/belly than your back, but your front is where all of the pressure *or really lack of pressure from the air in the suit*. Dense is good in this case because of resiliency.

 

[Lorenzoid]

So theoretically, if one could maintain oneself centered within an air bubble, that would provide maximum insulation? In other words, in an ideal or theoretical case, there would be no fibers at all?

 

[stuartv]

sorry, thread seemed derailed so I didn't pop in. Thank God @The Chairman put a tagging feature in for stuff like this. I usually start ignoring threads after the third page or so unless I get tagged

Ok, so air is what we are using to insulate. Without using active materials like phase change materials that can heat/cool under certain conditions, we are using passive insulation to create an air barrier between the water and our skin.

The ideal solution is something pillowy because that has lots of air and will insulate very well. Downside of this is there is basically no resiliency to this kind of solution. I.e. it doesn't "spring" back when put under pressure, and it has no ability to insulate when compressed.

Next solution is to take something really resilient and make it lofty. Felts are typically how this is done i.e. things like polartec.

so, what happens here is that when the pressure from your suit goes against the fabric, the dense felt compresses less and ends up holding more air than the light pillowy fabric and gives you an extra barrier against the cold. This can be made better by things like hollow fibers *DuPont's Thermax* which holds some more air.

You want more insulation around your chest/belly than your back, but your front is where all of the pressure *or really lack of pressure from the air in the suit*. Dense is good in this case because of resiliency.

So, you're saying that if you are equally warm in a dense undergarment as you are in a poofy undergarment, then there is the same amount of air inside the suit?

The real question I thought was on the table is, does a poofy undergarment result in harder bubble management (when achieving the same amount of warmth)? I feel like the answer is yes, but it seems like you're saying the answer is really no.

 

[boulderjohn]

I would say there is more happening with the undergarment than is being given credit here.