Problems Venting A Drysuit on the Ascent

[shurite7]

I had similar issues with my ascents and here is what I found.

Do you use a weight belt?

I found the weight belt and my harness restricted airflow from the lower part of the dry suit to the left arm. I went from an aluminum tank to steel in order to eliminate my weight belt and that was the cure.

Cheers

Chris

 

[Todd128]

If you are overweighted, you may potentially be pumping way too much air into your DS to achieve buoyancy control, especially at 100' as you suggest. During an ascent that is too rapid, I found the expansion of all of this gas can potentially overwhelm the release valve, potentially requiring one to squeeze the suit to the force air out of air pockets in the suit more quickly, as you described. Getting rid of 4 lbs made a big difference for me. Ascending very slowly, with arm carefully raised and positioned to continuously vent, helped.

 

[dave4868]

Snipped part of your quote....You add and subtract air from your suit to keep it's volume constant (just barely feel the squeeze) and you add and subtract air from your BC to ballance the weight of the gas in your tank(s).

Which one is "buoyancy control?" I think that they are both part of a good diver being able to control their position in the water collumn.

The side discussion was that there is more than one effective method for controlling buoyancy when diving in a drysuit. There are benefits to both methods.

Since I don't have any problems with air shifting or venting, I prefer to use only the drysuit for buoyancy control because I find it's simpler and more convenient....and possibly warmer.

Now I'll carefully take my foot off this hijack banana peel...

Whew!

Dave C

 

[vetdiver]

My TLS 350 and CLx450 both vent fine with a thick Weezle Extreme Plus

Oh, the irony. My husband just had the exhaust valve of his DUI 50/50 blocked during an ascent (more accurately, a swim in, we had done a shore dive) by his Weezle undergarment about a month ago. He actually had to break a seal (fortunately, he had removed his hood and had an easy time of it) and flare to avoid shooting to the surface from about 30 ft. He now has duct tape on the arm of his Weezle. As I'm sure you have heard, this has been reported with Weezle undergarments.

WKenny, I dive a CF200, and I also have to lift my left arm to vent when I ascend. I do not use my suit for buoyancy, and I also don't wear hi-loft undies. During shore dive swims in, I will even use my right hand to squeeze excess air out of the arm of the suit, something I have only seen one or two other divers do around here, but most of my friends dive TLS's...maybe the crushed neoprene suit is a bit more thick/stiff than the TLS, but who knows. Doesn't bother me at all.

 

[Todd128]

He now has duct tape on the arm of his Weezle. As I'm sure you have heard, this has been reported with Weezle undergarments

I have Weezle underwear with a Viking drysuit. What exactly is the problem with the underwear, and how might one test the specific problem? I haven't noticed anything so far that couldn't be attributed to my own errors and my own skill level...Todd

 

[TSandM]

The nylon taffeta outer layer of the Weezle has been reported on occasion to get sucked into the orifice of the exhaust valve and block it. I had read that Weezle changed the fabric from the original offending one, but I don't know if that's true. Some people who use them put duct tape over the arm where the dump valve is, which prevents the problem. I suspect most of the problems people report with Weezles are simply because of the amount of air they require to loft and insulate properly, and how slowly that air moves out of the fabric to where you can dump it.

 

[dave4868]

Oh, the irony. My husband just had the exhaust valve of his DUI 50/50 blocked during an ascent (more accurately, a swim in, we had done a shore dive) by his Weezle undergarment about a month ago. He actually had to break a seal (fortunately, he had removed his hood and had an easy time of it) and flare to avoid shooting to the surface from about 30 ft. He now has duct tape on the arm of his Weezle. As I'm sure you have heard, this has been reported with Weezle undergarments.

Partially blocked perhaps, but the outer shell of my Weezle is breathable. Try breathing through yours. If yours isn't, maybe that's the problem.

Could there have been other factors in your husband's case?

• Sticky exhaust valve
• Tight shoulder straps
• Tight weight belt
• Tight-fitting suit
• Attitude in the water
• Significant underweighting or overweighting
• Dampness of the garment's outer layer
• Delay in trying to vent

Maybe you have ruled out all of these potential factors, but any of them could contribute to slow venting.

Must have been disconcerting for you both, but it might be a little early to blame the fabric entirely.

Can you post any references to the reports you mentioned?

All I found was:

http://www.scubaboard.com/archive/index.php/t-9154.html

It appeared to be rumor-based and reactionary and dramatic, the kind of stuff that propagates urban legends.

I've never had a problem venting my Weezle Extreme Plus, even though I usually dive a somewhat sawtooth pattern in water less than 30' deep, wear an additional 100 gram polypropylene base layer, wear a lot of lead including about 5 lbs of "excess" weight (54 lbs total in the winter) and use only my drysuit for buoyancy control.

Dave C