Breathing gas sometimes coming out of my nose in CCR diving. Mask issue or OPV ?

[JackZwykle]

As I mentioned in the thread you linked I have experienced it as a saxophone player, as a result of fatigue. Usually if I'm out of practice and suddenly play for many hours without building up the stamina. That makes me think it's muscular fatigue and something that can be trained. I don't know if it's feasible to dive the CCR often enough to train these muscles, or if some other practice like blowing into a tube in a water bottle (common exercise for brass players and singers) or actually playing a wind instrument would be required.

My 5 cents no-one asked for :

I would love to learn how to "train" that muscle, because I suffer badly from it, but rather randomly.
It mostly happens in very cold water if I was very tired / stressed to start with, but that's not a rule.

Other than that it's completely random, can happen 15 mins into the dive or 4h.
I can get it 4 times in a month and then not once for a year.

And I dive OTS/BM CL, so lowest possible pressure in the nasal cavity together with BM.

The only thing I can try and do when it happens is change the position and really minimal loop to create constant negative pressure in the BOV and then I don't lose the dil, but I'm then very restricted visually, positionally, so typically it's the end of the dive, slow and safe, but the end.

I see no rhyme or rythm to when it happens apart from extreme stress / tiredness, but that's expected I guess.
And if anything - it's getting worse with age, which stresses me out a little.

Any anecdotes, excercises to strengthen that velopharyngeal lock?

 

[steinbil]

This is the exercise I was alluding to, that is very common for singers. It's not actually meant to help the velopharyngeal lock, it's more for breath control and relaxing the vocal folds, so the two giant caveats are:
- this is not what the exercise is for
- according to doctors, "Blowing, sucking and oral-motor exercises are not effective in improving velopharyngeal closure"

 

[happy-diver]

I think I've held my nose for a bit and sucked my cheeks in unlike Louis Armstrong but I can't remember

 

[dahab boris]

As someone with as much as 1 CCR dive (and an upcoming class!) I'm a bit surprised to read of the OPV. I spent most of my dive making sure I had "minimum loop volume", thus there wouldn't be any triggering of an OPV - so is there differences to you unit or? Genuinely curious

Minimum loop