Low Volume/High Volume Masks

lakelanddiver1978

I need a little help. I have been diving for quiet a while now (Advanced Open Water Instructor) but am new to CCR. I have always used an Aqua Lung Tri-View mask. It is very high volume mask and looks like it is something out of Sea Hunt. While flooding and mask squeeze was never an issue while diving OC, I have a great deal of difficulty with mask squeeze and with getting my mask to seal properly. Again, this is never an issue diving OC, but has become a real pain while diving CCR.

I have searched for discussions on this issue and have seen some references to using a low volume mask. Does anyone have any further thoughts/help on this issue? I can't keep blowing through Dil clearing my mask or having my eyes bug out from squeeze.

Thanks for any help you all can offer,
Justin

Abbo

In my humble opinion, a mask..is a mask..is a mask. The one I use most at the moment I bought dirt cheap in Thailand: a local brand. If you're the kind of chap that likes to drive around in a taxi throwing money out the window you might go for a fancy mask but, well, they're just windows. There's no reason why a fancy mask should fit better than a cheap one: it just depends what shape your face is.

In most shops they are all out of their boxes hanging on the wall. Go through them all. Offer each one to your face, suck in through your nose and see if it sits there on your face. If it falls off, where was the air getting in: most likely it was your moustache. No drama there that soap, water and a blade won't fix. No point sucking your eyes out of their sockets and looking like Marty Feldman, though.

Most masks leak a little. As long as it's only a little I leave it there: sometimes it's useful to wash your windows with. If you're using so much dil that it makes a meaningful dent on your gas use you might be overdoing the mask clearing: you're trying to ease the water out of the mask, not shoot it into the asteroid belt. Sure, you'd use a bit less gas clearing it if you had a lower volume mask, though.

Mixaddict

It is a bit of an adjustment with the mask when you switch to CCR. IMHO, a low volume mask is easier to deal with, especially when diving CCR - less volume to clear, easier to equalize, less drama overall. It may take you a few dives to get used to the new mask, but I think you will find the low volume mask is more typical for tech divers and especially CCR divers for the reasons stated above. Just make sure the thing fits you well in the first place. Right now I am diving a Dive Rite mask and I love it.

Just my $.02 (worth exactly what you paid for it!)
Regards,
Randy

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Randy Thornton (MixAddict)
Inspiration, Evolution,Hammerhead & Sentinel
CCR Instructor

ScubaDadMiami

I agree with the Addict on this one. If what you have doesn't work, find a new mask that does. The lower the volume (but all other fit factors being equal), the better. If you bring your DSV to the shop so that you try on the masks with your face as it will be when breathing from the loop, this will help find the one that will seal the best in the real world.

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Howard Packer
IANTD CCR Instructor
Miami Beach, Florida
CCRDiveTraining.com

decoweenie

Justin,

IMHO, it has nothing to do with mask. Using any mask will lead to the same.

What you need to learn to do is STOP breathing with your nose on CCR.

By breathing in/out with your nose unconsciously and intermittently, you affect its volume thus the reason for the mask squeeze as well as blowing diluent out from it.

If you are diving with CCR divers with more hours, try to compare them to those with lower hours. There is less leakage from those been diving it longer, those who are new will "snort" gas out or have a trailing of small bubbles from their mask throughout the dive.

As an instructor, you know that masks are personal preference items that not one single model will fit all individuals so it is difficult to recommend the "best" option. Having said that, I have been using the Scubapro frameless mask (and its cheaper copies) for 10 years and loving it. Just FYI...

colinicky

I would agree with decoweenie ,when I went from OC to CCR I was doing the same as yourself blowing dil & wondering why everybody else was only using 20 bar to my 120 bar ! I even went to the pool & got somebody to video me on OC & CCR & it proved that sub conciously on OC I was breathing out through my nose .It was actually very hard to stop this without concentrating very hard ,it took a lot of dives to retrain my mind .
Also as Scubadad if you decide on a new mask take the DSV with you to try the masks as certainly the Inspiration mouth piece is bigger than a lot of OC regs .

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Colin

I trust my rebreather completely ,
I just don't trust the user

onwards & downwards

nigelh

The only mask problem I had was the lovely Cressi Big-Eyes that I bought just before going CCR was wasted because all my added 'down view' was blocked by the hoses. <sigh>

Yes. Everything they say about nose breathing is true. Most of us had to break the habit. I don't see any reason to go for low volume though as equalising a mask doesn't take significant gas on any form of scuba. However, I admit, a really low volume mask did put 15 meters on my freedive comfort zone.

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nigelh

sasmedic

Hi Justin


From personal experience I must agree that the best mask is not necessarily the most expensive one, but I think the mask fit is even more important for Rebreather than OC diving due to the dil issue.

I use a cheap low volume mask that are the best I have ever used. The thing is that I realized I should look for something that are better due to dil that can be wasted when water seeps in. Seeing that as the primary cause of the problem. As soon as water seeps in I want to clear it due to eye sensitivity and to avoid being in a position to not see gauges, signals, etc. Apart from the normal mask selection criteria I added to more that I encountered underwater. One is smiling and the other is chipmonk cheeks. Once I found the mask that could handle these as well I without allowing inseepage of H2O I was set.

Once the mask is not part of the problem ito dil waste then you can fix your mind on not breathing through your nose. That was the basis of my approach to solving the issue.

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The best cure for fear is knowledge!!!

Sutty

There's a few old threads on inadvertant nose breathing that may be of interest/help with this.

Here

Here

and Here

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Never forget that life is a finite resource.

PaulTG2

Hello, I had the same problem when I started diving CC. I dont' know if I did the same thing on OC, or if the breathing difference in CC cause me to breath as I do on the surface. I don't think I've had a problem with nose breathing on OC, but it is possible that CC makes it more of a problem. In fact, my first non-instruction CC dives were extremely uncomfortable because of mask leaking issues. It appears I was relaxing enough that I didn't keep enough negative pressure in my mask and it leaked. I had to retrain myself and now things are usually ok. --p