Hi Guys. So I finished my CCR course about 3 months ago and I got about 20hrs excluding training. My unit is a liberty BMCL. I have been having excellent experience with this unit, but the only issue is that I usually start getting sines bypass(According to my instructor) after about 60mins into the dives. Which means that I start to be unable to control my nose and start to breathe using both mouth and nose and keep sucking in my mask. It has nothing to do with my lung volume because I got plenty of it and the ADV isn't going off. It has nothing to do with heads-down trim because I usually dive head up a little bit (20 degrees) for better work of breathing(Due to the BMCL). It also has nothing to do with any medical problems because I checked with doctors before and my nose/sines is completely fine and I experience no issues of any kind in life with my nose(No running nose every day, no regular bypass, no medical conditions...) During my course I checked with my instructor and my instructor said it's due to a lack of practice. But I am still getting it now. Had no idea what is wrong with this and kinda eager for a solution since this becomes the #1 reason for me to terminate a dive or feeling uncomfortable during a dive. Thanks for any help.
nasal sines bypass for a long rebreather dive
- Thread starter alanchang
- Start date
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broncobowsher
Contributor
Does it match this?
scubaboard.com
Has anyone had a “free flowing” nose on a rebreather?
To preface, I am a relatively new rebreather diver (only ~20 hours on the unit). On three distinct dives, with all three being more strenuous or task-intensive, I’ve had an issue where my nose will begin to “free flow” or “vent” on inhalation. My first reaction was to reduce loop volume...
No. But thanks.I had a different issue. After an hours or something I started to get running nose and mucus and can't control my nose anymore.Does it match this?
Has anyone had a “free flowing” nose on a rebreather?
To preface, I am a relatively new rebreather diver (only ~20 hours on the unit). On three distinct dives, with all three being more strenuous or task-intensive, I’ve had an issue where my nose will begin to “free flow” or “vent” on inhalation. My first reaction was to reduce loop volume...
TuckerIdaho
Contributor
Seacure mouthpiece solved this for me.
On realllllly long dives I’ll bailout for a minute per hour and it tends to clean/dry me out, but it is generally not a problem on shorter dives or when I am not experiencing seasonal allergies.
J-Vo
Contributor
For me, this stopped after about 50 hours on the loop over maybe 6 months. Sometimes I'll get a little hint of it again if I have dove several consecutive days without good rest at night. I thinks it's some type of muscle fatigue. You just need to train it up and then maintain it.
I thought it was a gimmick but after only a few mins with Seacure, I felt a difference.
I get this on my rEvo. When I was new to CCR, I got it more easily. Now, with 250-ish hours on the loop, I still get it sometimes.
For me, it happens when I swim in perfectly flat trim (versus a little head up) and work. The last time it happened was after swimming over 2 hours into the flow on a cave dive at Ginnie Springs. It got so bad I had to turn the dive. It also can happen to me if I spend prolonged periods during a dive in perfectly flat or slightly head down trim. If I'm flat and/or slightly head down a lot, it can start to happen to me before the end of a 2nd 1 hour dive in a day. I.e. 1 hour dive is fine. Get in for a 2nd 1 hour dive and keep diving in that same trim and I start to get it.
Then I got a Choptima (aka Dive Rite Optima CM chest mount CCR).
Right after I finished my CCR crossover to the Chop, I went back to Ginnie and did a 4 hour dive with not even a hint of trouble breathing.
My point: Yes, you can keep dealing with it and it will probably get *better*. But, it might never go away. You might just need more time on the loop. Or, you might need a CCR that breathes better. Or some over-the-shoulder or chest-mount counter lungs for the CCR you have.
My Chop breathes awesome and it is my go-to for cave diving now. But, I still dive my rEvo for just about everything else. It all comes down to picking the best tool for you, for the job you are doing.
I'm considering applying some strong medication that forcefully prevents my nose from generating any gunk when applied. I think that will help. I know a front-mounted counter lung will help but I don't want anything all over the chest area because I mainly do cold water diving and anything over the chest will bring me a hard time to reach stuff/access to D ring and takeoff/put on stages. and No I don't believe my liberty is hard to breath because I find it really easy except It's giving me nose issues.
Yep.... when I first got my rEvo, I FIRMLY believed that it breathed just fine. NOBODY could tell me differently.
I do agree about wanting a clean, uncluttered chest. That is why my rEvo is still my primary unit, even though the Choptima generally breathes better. The rEvo breathes plenty good ENOUGH for what I use it for.
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