Confusion about back inflate BCDs & dump valves

[swimmingpooldivein]

Hello!

When I'm diving with a jacket BCD and using the dump valve at the bottom of the BCD, I can easily and immediately confirm that I'm pulling the cord hard enough and that air is being released because I can feel the jacket getting smaller under my arms. But when I use a back inflate BCD, I have no immediate confirmation that I'm pulling the cord hard enough, and that the BCD is actually deflating. How do you compensate for this lack of confirmation in a back inflate BCD? Thanks!!

 

[Cheizz]

I can hear and feel the bubbles coming out of the bottom dump valve when I pull the cord. Also, I notice the effect in my buoyancy.

 

[Norwegian Cave Diver]

My Halcyon Eclipse dump is bottom left. I stick my right shoulder down and my left butt up. Should be able hear the bubbles dumping.

 

[lexvil]

So one would presume you are venting for a reason, perhaps being to floaty, in which case as one becomes less floaty one may assume there is less floaty stuff in said b/c.

 

[Ski_Lounge]

It might also help to "time" the pull-dump so you are not in the midst of an exhale cycle. The sound of bubbles from your pull-dump is softer, and easily overwhelmed by the sound of bubbles from exhaling. (Obviously, don't hold your breath, but align it with your inhale.)

 

[NaCl H2O]

To add what Lex said, wait a few secs. You should feel the bouyancy adjustment.
Unless you are descending use small burps or adds as needed.

 

[inquis]

If you grab the string near the valve, you can easily feel the bubbles exiting. If you pull from the end of a long string, you may not. As others have said, listen for them as well between breaths.

I put a knot about 1 cm from the valve and "pinch" the cord (fingertips on the valve) for a precision release. (I left about a 1 cm tail and cut the rest off.)

 

[CT-Rich]

I have been using a back inflate for about 10 years. You can feel the bubbles leaving the valve, just like you can feel gas flowing into the BCD when you hit the power inflate.

 

[undrwater]

If you're wearing a thick hood, it is sometimes difficult to hear whether air is coming out of the valve. I had the same issue early on.

If you shorten the pull dump cord, you'll be able to feel the air escaping with your hands. Eventually you'll be more sensitive to your buoyancy, and be able to better tell without having to feel or hear it.

 

[swimmingpooldivein]

Hey everyone! Thank you so much for all the great advice! I appreciate it

I used a back inflate BCD again this week, and I realized I can feel the vibrations from the bubbles on the hand pulling the dump valve. It is very mild though, and it requires deep concentration. Hearing the bubbles is even harder, with the underwater marine life chatter, humming from the dive boat, my own or a nearby diver's breathing, ... And yes @undrwater, I do wear a hood!

Maybe it's just not the right BCD for me

So one would presume you are venting for a reason, perhaps being to floaty, in which case as one becomes less floaty one may assume there is less floaty stuff in said b/c.

Yes, totally right! I was trying to highlight in my original post that I'm looking for immediate feedback that doesn't involve me waiting the 1 to 2 seconds to confirm my buoyancy as changed. For example, if I don't time it with my breathing, I think nothing happened, I pull the dump valve again, and I'm positively buoyant.