JJCCR Exhale lung OPV alternative?

[mr_v]

So, you must throw away your drysuit's OPV.
Waiting until the OPV decides to dump a random amount of gas from a very full & buoyant drysuit seems like a way to have a very rocky BO ascent.

You can be serious about it, right?

Buoyancy control is a proactive action, it is a lot like reefing sails, braking before entering a corner, covering your mouth before sneezing, or pulling down your pants before pooping. You do all those things before the main act.

The example of uncontrolled ascend due to a stuck OPV says a lot more about the diver's skills and the pre-dive procedure than about rebreather design.

 

[Alekseolsen]

The example of uncontrolled ascend due to a stuck OPV says a lot more about the diver's skills and the pre-dive procedure than about rebreather design.

Afraid you *really* missed the point

 

[Tracy]

I have had units with the adjustable drysuit style dump and always kept them cranked closed as them would leak at inopportune times resulting in a buoyancy shift I wasn't expecting.
I have installed pull cord dumps on all of my current units and prefer that style.

 

[mr_v]

Afraid you *really* missed the point

Could be that. Ganja cat is a bit high today.

 

[rjack321]

So, you must throw away your drysuit's OPV.
Waiting until the OPV decides to dump a random amount of gas from a very full & buoyant drysuit seems like a way to have a very rocky BO ascent.

People don't wait for their suit to fill up like a balloon before venting as an OPV - unless they are corking uncontrolled to the surface

 

[Snusmumrik]

People don't wait for their suit to fill up like a balloon before venting as an OPV - unless they are corking uncontrolled to the surface

IMHO - people don't wait for their CLs or suit to fill up like a balloon.
Automatic drysuit OPVs lessens operational load during ascent.
Pull-style OPVs adding inevitable things to avoud uncontrolled ascent.
Me prefers less operational load.

 

[rjack321]

IMHO - people don't wait for their CLs or suit to fill up like a balloon.
Automatic drysuit OPVs lessens operational load during ascent.
Pull-style OPVs adding inevitable things to avoud uncontrolled ascent.
Me prefers less operational load.

OPV = OVER pressure valve. It's only going to vent when the CLs are full

 

[Markus MDDT]

I think the OP might be talking about options under bailout scenarios, like being able to just tilt-dump hands-free, rather than pull a [possibly missing] cord, or manually vent a closed bailed out loop?

Correct.
Thats exactly what im asking. Thanks!

 

[Markus MDDT]

IMHO - people don't wait for their CLs or suit to fill up like a balloon.
Automatic drysuit OPVs lessens operational load during ascent.
Pull-style OPVs adding inevitable things to avoud uncontrolled ascent.
Me prefers less operational load.

I agree. I think operational load or task loading is underestimated as risk and I think mitigating this by doing robust automation is one way of freeing up "RAM" for problem solving during an emergency.

 

[Markus MDDT]

I have had units with the adjustable drysuit style dump and always kept them cranked closed as them would leak at inopportune times resulting in a buoyancy shift I wasn't expecting.
I have installed pull cord dumps on all of my current units and prefer that style.

That is interesting and very useful info to me. I haven't had the opportunity to talk to anyone using the adjustable opv. I was wondering excactly how useful they are during "real" diving. Would you say the leaking is due to a malfunctioning opv or just the nature of the design, that it is hard to set the correct release pressure?