Cuff or Shoulder Vent for Dry Suit?

[Soggy]

My understanding is that we were talking about a cuff (as in wrist/forearm area) dump vs a shoulder dump, (i.e., a placement issue). When I hear "cuff dump" that is what I think of. It seems some are talking about a non-adjustable dump vs an adjustable dump, which is a function issue. Which is it?

 

[String]

Ive never seen an adjustable cuff dump. Its a simple bit of plastic with a membrane in. No springs, nothing. It dumps when internal pressure is great than external, in other words, whenever its the highest part of the body. Typically this means lifting the arm/wrist 1/2 inch up from horizontal.

The so called "auto dumps" ive only ever seen on or near the shoulder. Ive still never seen one in the place where it will automatically dump without some rolling or contorting - after all, air will only dump when its the highest point which unless youre vertical or swimming on your back isnt the front shoulder or forearm where most manufacturers fit the things unless you have a VERY tight suit around the shoulders.

 

[KenJr]

I am new to diving and just purchased my first dry suit (have not even used it yet).
Is there a reason a person could not have both a cuff and shoulder vent on the same suit.

 

[Tobagoman]

I've been diving drysuits for years and have to admit that I have never used a cuff dump, and have never had an issue with my 'shoulder' dump valve. I've never had to contort myself to dump air from the suit and most of the time don't have to mess with the valve. When I am surfacing I am usually in a heads up position anyway and a little chicken wing raise of the shoulder with the valve is all that is needed to exhaust the expanding gas in the suit.

 

[Henryville]

PM Jagfish on this board. He had a TLS 350 changed over from shoulder to cuff dump and I believe has some pretty clear opinions about the switch.

 

[Rickster]

Shoulder dump here. No problems, and works great.

 

[audibleatom]

I have had suits with both and i prefer the shoulder valve...I work for a major drysuit manufacture and find that 1% (my opinion) use a cuff dump. We build suits with cuff dumps but they are on non-divable suits. (Coast Guard rescue swimmers) As far as a surface suit they work great, but for diving i found it to bug the hell out of me.

 

[String]

I am new to diving and just purchased my first dry suit (have not even used it yet).
Is there a reason a person could not have both a cuff and shoulder vent on the same suit.

No there isnt.

Ive got both on my suit (i dived the auto, hated it, fitted a cuff and just didnt bother removing or blanking off the auto). Theres no reason you cant have both on the suit although there isnt really any reason TO have both either unless like me you never bothered blanking a hole off.

With a membrane suit fitting a dump of any sort is dead easy and a 5 minute do-it-yourself job. Neoprene is slightly more complicated with stretch but still a fairly easy task.

My cuff dump cost me roughly $18 usd to buy.

 

[Soggy]

My cuff dump cost me roughly $18 usd to buy.

Please define what you mean by "cuff dump." As I said before, I think we are having a terminology problem.

 

[String]

Its a simple plastic dump smaller than an auto dump (which you term shoulder dump) that lives on the cuff (either on the inside of the arm or outside - personal choice as to where really).

Its not no spring in it and has no adjustments. Its basically a plastic valve that screws with one half on the inside, the other half outside the sleeve and all thats in the middle is a flexible rubber-like diaphgram.

Operation is simple in that when the internal pressure exceeds the external pressure on that particular area the air lifts/flexes this bit of rubber and the air leaves. When that changes the thing rebounds and re-seals.

In practice this means any time the wrist is the highest part of the body it will dump air (due to air migrating to this area etc). This means when swimming along lifting a wrist 2 inches or so will be enough to dump. Lower wrist to cease dumping.

Theres a picture of one here:

http://ccgi.apvalves.plus.com/accessdetail.php?codeID=68

Its not terribly clear though.

If that doesnt answer the question i'll photograph one of mine tomorrow (as i need to take them off the suit anyway to clean them after a week of grit and sand over the suit).