Nasal pressure issue

[Coll]

I recently got certified on 100% O2 rebreathers and am having some issue. We dive C.O.D.E.S. and OxyLungs and from time to time on dives I have to consciously force myself to close my nasal passage because it feels like all my body wants to do is exhale through my nose, what ends up happening is I get this kind of creaking sound from the force it takes to control my breath and I end up having to call the dive. Any help would be much appreciated!

 

[Thalassamania]

I've never experienced that. I dive an old Carlton Cobra, where did you get trained on the USD gear? I didn't know that there were many other civilian Oxygen CCR divers out there.

 

[Coll]

Hey Thal, definitely not a common cert, that's for sure! I work as a civilian contractor for the US Navy which is where I got my training. For future reference, the next day I knew I was diving the CODE again so I did everything I could to clear my sinuses, I also wore my rig higher up on my chest, much higher than I normally would and I refocused my weighting to have a little more weight towards my legs to make sure I was exactly horizontal. As it turns out, my buddy said that on that troublesome dive I was slightly vertical in the water. I'm not sure if it was one of those things or a combination of them but I had no problems on that next dive. Thanks for your interest!

 

[Thalassamania]

Hm ... I used a Pirelli years ago, chest mounted but pendulum, never had a problem like that. My Cobra is a back mount.

 

[Coll]

I haven't dove a back mount, I imagine your valve is still on the front? Or on the hip? It's a 100% O2 rig or a mixed gas? What do you dive it for?

 

[Thalassamania]

It's 100% O2, I dive it for shallow, quiet, fun.

 

[Coll]

Definitely a good use for it! How big is the bottle on the Cobra?

 

[Thalassamania]

It had been modified for work around Isla del Sol in Lake Titicaca, so that a 50 cubic foot Aluminum cylinder can be mounted horizontally on the bottom, permitting multiple dives without refilling.

 

[Coll]

Very nice! That must give you a lot of down time.

 

[Thalassamania]

Yeah, I can easily take it out the OTU limit on successive days wthout having to refil. Now if I could just find a scrubber that would go a lot longer.