Has anyone had a “free flowing” nose on a rebreather?

[PEDiver]

High workload, increased gas density, and likely a bit of stress managing new equipment (playing with the DPV and in your course) can all attribute to CO2 buildup.

I’ve found this issue to be more common on FMCLs (increased hydrostatic WOB on the exhale) and especially units with smaller loop volumes (much easier to over breathe).

Keep work loads extremely low in the future and if you feel yourself starting to breathe hard, stop all activity and rest until it is under control, and use adequate He for deeper dives (18/45 would be a more appropriate mix for dives in the 150ft range).

All great points, thank you. It sounds like the likelihood of it happening on a BM unit are lower (assuming you keep workload to a relative minimum to reduce CO2)?

Like I said, I'm relatively new to rebreather diving and the Choptima, and while it has been a great unit so far (easy to assemble and maintain), I don't love the real estate it takes up on my chest (coming from BM doubles originally). Been debating on switching to a BM unit or just continuing to build hours on the Choptima.

 

[PEDiver]

I have had some "snorting" and you could feel the mask cycling in and out as I breathed. Happened a fair bit when I first started on the rebreather. No so much anymore. I recall there was good info on it on rebreatherworld.com, back when it still existed.

That sounds very similar to the issue I have had, including the mask "cycling." What unit are you diving?

 

[Blackfrogfeet]

That sounds very similar to the issue I have had, including the mask "cycling." What unit are you diving?

I get it as well. I'm on a Fathom. It's just the fatigue of the muscles involved with closing off the nasal passage. When I'm diving regularly it doesn't happen as much or at all. I recently took some time off, and it started again.

 

[billgraham]

My friend who teaches would say you need to work on your "eye-nose coordination".

 

[JonG1]

I'm on a BM unit and used to have the opposite, i.e. snorting and de-ressurising the mask, so the opposite of you but possibly the same cuase due to the relative hydrostatic loads, I think it was partly due to a relaxation of facial muscles and soft palate due to a gag strap, very rare now and solveable if it happens by a tighter grip on the mouthpiece

 

[broncobowsher]

That sounds very similar to the issue I have had, including the mask "cycling." What unit are you diving?

rEvo.

 

[mr_v]

I'm on a BM unit and used to have the opposite, i.e. snorting and de-ressurising the mask, so the opposite of you but possibly the same cuase due to the relative hydrostatic loads, I think it was partly due to a relaxation of facial muscles and soft palate due to a gag strap, very rare now and solveable if it happens by a tighter grip on the mouthpiece

Did it sound like you were animal noises? I experienced that once... was really odd and I tightened facial muscles to fix the sounds.

 

[broncobowsher]

Did it sound like you were animal noises? I experienced that once... was really odd and I tightened facial muscles to fix the sounds.

It did for me. The snorting noises I referenced.

 

[JonG1]

Did it sound like you were animal noises? I experienced that once... was really odd and I tightened facial muscles to fix the sounds.

Very much so, and was pretty disconcerting

 

[Wibble]

Me too. Snorting noises. Diving a Revo.

As others said, seems to be the soft pallet muscles having a rest for a few minutes. Doesn’t happen very often and seems to go away when I stop thinking about it. I have a BOV and wonder if it’s related to the loop being a little heavier and stiffer with the additional regulator LP hose, can’t say if I noticed it with a DSV.

Seems like water is getting in to my nasal passage but more related to the soft palate not sealing -- like having a lot of snot after sneezing. Not noticed fatigue or aching, just that the snorting is annoying and uncomfortable.

Hadn’t thought about holding the mask tighter to seal the nose, nor holding the nose.

Quite pleased this has been posted as I thought I was the only one who’d had this happen.