full face mask and air consumption?

[kayakguy]

For those of you using a ffm, how would you say that your air consumtion has changed? I fear that it may be drastic. Thanks in advance.
-Bryan

 

[mntdiver]

Bryan,

There are lots of opinions on this and it does depend on what equipment your using. Mostly, it's going to depend on the fit you get with the mask and your comfort level. CO2 washout is something for consideration as well. Masks with poor washout will cause you to breath harder, this due to residual CO2 keying your breathing rate. A poor fitting and burping mask will obviously raise your gas consumption as will how much you talk, if you're using communications equipment. I find that I use about the same as with a bite mouthpiece. This wasn't in the beginning though. It was several months of diving a full face mask before I got to this point. My wife and I dive AGAs and when we're on dive boats, we are routinely the last ones back.

Avoid positive pressure, not necessary for diving. And if you haven't picked a mask yet, do a lot of research, not all full face masks are created equal.

 

[DA Aquamaster]

I agree. Positive pressure is not required and will increase air consumption, as will gabbing on a com system. Otherwise if CO2 is not an issue and the mask does not leak, air consumption should be comparable.

 

[muddiver]

Most divers will probably experience an drastic increase in air consumption when they first try a full face mask just because it is really different and causes some anxiety. Each mask is different and some are designed much like a regular SCUBA regulator. Others are not. The only real change is the increase in buoancy caused by the larger air space in the mask which might have to be compensated with an extra pound of lead. Professional divers will say a full faces causes the diver to use more air. What they fail to take into consideration is that professional divers use more air because they are usually working and must breath harder. For recreational (relaxed) diving the full face mask should not cause any increase in air consumption. The regulator on the mask is the same as any other SCUBA regulator (with the exception of the AGA positive pressure option).

 

[Colliam7]

CO2 washout is something for consideration as well. Masks with poor washout will cause you to breath harder, this due to residual CO2 keying your breathing rate. A poor fitting and burping mask will obviously raise your gas consumption as will how much you talk, if you're using communications equipment. ... And if you haven't picked a mask yet, do a lot of research, not all full face masks are created equal.

Very good advice! My first experience with a ffm was challenging. I felt like I was suffocating at times, and overbreathing the regulator to get enough air. So, my gas consumption increased, although I am not sure it was a true increase, because I also picked the wrong conditions to try ffm - relatively new to my drysuit at that point and still working on weighting and trim - and the first one I tried had comm. So, if you are dialed in well with your rig, and you do the background research, you will be in good shape and I don't know that you will see a dramatic increase.

 

[Doc]

Of course your air consumption will increase, probably 2x or so.

I mean, do the math. When you're on land you can easily get enough air out of one or the other, your nose or mouth, so it only stands to reason...

If you are breathing out of all three holes, you'll use up twice the air.

Relax... it will come in time, and very soon. For many applications, it is quite relaxing and easy on your body. It will likely decrease.