A little teeny weeny exhaust cuff valve...

[Bopper]

I just bought a used Northern Diver drysuit at a fantastic price. It's in excellent condition and has some nice bells and whistles (trilam, cuff system, integrated boots, over zipper, etc). I was so happy with the deal I didn't make too much out of the fact that it didn't have the standard adjustable exhaust valve on the left shoulder. Instead it has a smaller (1.5" diameter?) non-adjustable exhaust valve on the right cuff, and that's it. So you just raise your right arm and it's supposed to vent.

Just wanted to get other people's experiences with this type of setup. Does the valve vent quickly enough? Is it awkward to use?

On kind of a related note, I'm new to drysuit diving and I'm working out my buoyancy issues. One of the preferences I've settled on is to have the adjustable valve closed all the way (on my current drysuit which does have an adjustable exhaust). To let air out, I roll to my right slightly and 'feel' the bubble rise into my left shoulder, at which point I gently push down on the exhaust and air comes out.

But from what I've briefly read it seems as though many (maybe most?) drysuit users keep the valve wide open. How does that work? If you're descending, doesn't the add'l pressure force air out of the valve? Or let's say you're not descending, but rather you roll to your right. Doesn't air escape without your notice? Are there any other divers out there that prefer to have the valve always closed?

 

[TSandM]

I dive with the valve open all the time. Yes, if I go a little head up and roll to the right, I will lose gas from the suit, but I rarely assume that position unless I WANT to vent. Running the valve wide open works very well if you dive more or less horizontal, and properly weighted, so you don't have to have too much gas in the suit.

Regarding descents, rather than the pressure pushing the gas OUT of the suit, it compresses the suit. Remember that the gas in the suit starts at atmospheric pressure, and unless you add some, it stays there while the pressure outside builds. As you descend, you have to add gas to the suit to keep the volume in it constant. (Now, if you are descending in a vertical position, you have a bit of a problem, because all the air in the suit goes to the top and DOES bubble out of the vent. That's why most dry suit divers don't do their descents or ascents in a vertical position.)

I had a cuff dump on a suit a while back. It worked okay, but I found it annoying to have to lift my hand to vent, as opposed to just shrugging my left shoulder. If you carry a light in your left hand, it means the light is moving every time you need to vent, which can irritate your teammates.

 

[spectrum]

But from what I've briefly read it seems as though many (maybe most?) drysuit users keep the valve wide open. How does that work? If you're descending, doesn't the add'l pressure force air out of the valve? Or let's say you're not descending, but rather you roll to your right. Doesn't air escape without your notice? Are there any other divers out there that prefer to have the valve always closed?

I too dive wide open, maybe a click or to closed if I will down at a depth and want to hold a bit more loft. Otherwise wide open to enable a hands off ascent.

You are right that if you dip down the suit will auto vent and when you come back up you will be heavy and need a shot of air someplace. This is is unlike a wetsuit with will rebound or a suit with the valve closed.

An advantage of diving with the open valve is that you are less susceptible to a runaway ascent and usually avoid some task load.

Pete

 

[Peter_C]

I had a cuff dump for a few hundred dives and rather enjoyed it's benefits, especially while scootering. There are annoying parts to a cuff dump though. I can not see having a non adjustable valve no matter what the location of the valve is. I want to be able to close it. For instance at the surface I always close my exhaust valve and inflate my suit a little for comfort and buoyancy. So if it were me, I would buy a regular Si-Tech or the like and replace it. There are many times I want to close the exhaust down a couple of clicks, then working or having to constantly roll to look at someone on my left that is higher in the water column than I am.

Edit: BTW you could always move the exhaust to the shoulder if you wanted.

 

[Bopper]

Thanks for the responses. Nice to hear that someone had at least a "useable" experience with this setup. A new adjustable exhaust would cost as much as the suit, so at this point the game plan will be to try the wrist cuff dump and hopefully it works for me. Otherwise I'll gladly install a new valve in the shoulder.

And it sounds like I should give the 'open' setting on my valve another try. I somehow immediately got in the habit of pushing down on my valve to assist in venting but it sounds like for most of you its just a gentle roll and you're venting. Thanks again!

 

[spectrum]

I'll add that my wife went with the cuff position with a standard sized valve and likes it. The Statue of Liberty never had an uncontrolled ascent.

Pete

 

[Peter_C]

The Statue of Liberty never had an uncontrolled ascent.

Pete

Okay that made me laugh!