Dual Bladder Wings - A Good Choice for Redundancy?

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dewdropsonrosa

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No worse than 'splaining why the dual-bladder wing will be right back on the plate after class. :D


A ScubaBoard Staff Message...

This post was copied from GUE Fundamental course where discussion diverged from the original topic into a vigorous debate regarding the pros and cons of Redundant Bladder Wings. Those posts have been moved here.
 
No worse than 'splaining why the dual-bladder wing will be right back on the plate after class. :D

Out of honest curiosity why take the class with an agency if you have no intention of adhering to their philosophy? Certainty you can find an instructor who would be just as thorough with the skills coaching without any of the “unwanted” restrictions.
 
Out of honest curiosity why take the class with an agency if you have no intention of adhering to their philosophy? Certainty you can find an instructor who would be just as thorough with the skills coaching without any of the “unwanted” restrictions.

It's perfectly possible to want to learn another set of philosophies without intending initially to follow all of them. Plenty of religious people choose which parts of their religion to practice and adhere to, why should diving be any different?
 


A ScubaBoard Staff Message...

A portion of this post was copied from the GUE Fundamental thread.

On the specific subject of the dual-bladder wing:

I've spent some time researching GUE's institutional objections to dual-bladder wings. In their view (as I understand it), the extra bladder adds another failure point and discourages adherence to a balanced rig. I don't find their arguments persuasive.

Firstly, I think balanced rigs are a great idea and I've been working to balance mine over time. Where I disagree is that the second bladder can't be part of a balanced rig. My wing has a pretty puncture-resistant cover and I'm not usually diving near sharp things, so I don't think of this as a likely failure mode. Having a bad seal on the assembly, a button getting stuck, a QD breaking, a hose failing... all of these are more likely. These are equipment problems, and I don't see a problem with using an equipment solution to fix them. Primary bladder not functioning? Unplug primary bladder, switch the inflator hose to the redundant wing (self-sufficient solution), alert team and abort dive safely, seek repair.

Part of my cave training involved a "buoyancy bounce" exit - I had to safely make it back to the surface with a simulated wing failure. It was a frustrating but instructive experience: I'm confident that I can make it out alive, but it would be so much less stressful for me and any team members to do it with the proper redundancy.
 
Wait, really? I thought if you could swim it up after ditching your ditchable weight you were good; if you couldn't, you needed to reconfigure until enough of your weight was ditchable. So maybe a steel backplate, weighted STA, and steel tank would be OK (I still need 4 lbs. of lead on top of all that), but in switching to doubles you might need to rethink the backplate material or consider aluminum tanks. Am I mistaken?

That's my understanding too. Admittedly it's from an archived GI3 article however..
A diver must start with a balanced rig which gives him every chance to deal with emergencies. In ocean or lake diving, steel tanks should never be used without a drysuit. Double wings are an invitation to a disaster - do not use them. Elastic wings are a disaster waiting to happen. They can not be operated safely by mouth, they lose their gas if ruptured, they can not be breathed like normal wings, and they cause more drag than normal wings. For ocean, aluminum 80's are the tank of choice. If more gas is needed, take an aluminum stage, but don't risk your life being over weighted at the beginning of the dive. The buoyancy characteristics of aluminum, especially when using helium , are such that a weight belt and or canister light will provide the necessary ballast which can be dropped in an emergency, making the rig only reasonably negative when full, neutral when empty, but swimable by dropping the weight. In cave, steel must be used with a drysuit and they must be negative enough to allow the diver to stay down in a low on gas emergency. There is nothing worse than being too light to stay off the ceiling while low on gas and then struggling. For this reason, the rig must be balanced to a no gas situation prior to cave use, and weighted accordingly.
 
@Griffo (or anyone),

Double wings are an invitation to a disaster - do not use them

Anyone know the exact reasoning for this statement from GI3? I have no need for double bladder as I dive in a dry suit, but I'm more curious.
 
I've always assumed it was because of the possibility of uncontrolled inflation from two different sources, with the attendant difficulties in troubleshooting.
 
I've always assumed it was because of the possibility of uncontrolled inflation from two different sources, with the attendant difficulties in troubleshooting.
Looking at this RB wing: Dive Rite Classic Wing | Dive Gear Express®, I really don't see the issue. The inflator hose shouldn't be connected, so how would uncontrolled inflation occur?
 
I've always assumed it was because of the possibility of uncontrolled inflation from two different sources, with the attendant difficulties in troubleshooting.
I thought that you’d connect only one bladder at any time ?
 
Looking at this RB wing: Dive Rite Classic Wing | Dive Gear Express®, I really don't see the issue. The inflator hose shouldn't be connected, so how would uncontrolled inflation occur?
When you do have a leaking inflator you now have 2 to deal with (yes one isnt connected but you will still futz with both under stress)
If it isnt connected what good is it when you're dropping down the wall like a stone? So do you or dont you have muscle memory about what to do with it? (this is really the biggest issue)
If you do use the backup you have residual gas in the primary and are inflating the secondary now which will making venting one or both an issue
The right side inflator is bungied down right where your long hose clips off

The basic principle of Hogarthian is if you dont need it leave it at home. You dont need a dual wing.
 
https://www.shearwater.com/products/swift/

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