Dual-bladder or single-bladder? The whys and wherefores...

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I personally do not dive a dual bladder and rely upon my drysuit or liftbag for redundant lift. I believe that with a dual bladder it should have its own LP hose and be connected at all times. I also believe it should have a shutoff on it also. In the event of a stuck open inflator and the quick added buoyancy, you do not have time to unplug the hose just to find it was the other inflator leaking before you are in an uncontrolled ascent.

The redundant bladder will need to vigilantly maintained and inspected so that it really is functional when and if you have a bad day and need it. Many people just ignore them and just assume nothing could ever cause them to fail.


This should be in a manual
 
Incorrect. The outer covering is the limiting factor. There is only space for 40# of lift. If one wing is full there isn't room for the other to inflate. Use one or the other. You do not get double the lift with a dual bladder. You get redundant inflation of the same space. Trying to use both at once and you are now managing an extra air space making life more difficult for no good reason.


you and I are on the same page that quote is what some one else thought as to how it worked. I told them just what you posted. the outer covering is only so big and its volumn allowed for only 40# lift. then it made sense to him. Your other points I also voiced to him in the example of trying to use both bladders at the same time and getting too light. There are too many that thinks double sing provides additional lift in an emergency
 
when was the last time you dove a balanced rig? I can honestly say I have never in a cave since I use pretty thin undergarments... I never wear lead, but I chose to go to bigger backgas tanks instead of extra stages. If I was in Mexico diving with all AL80's, then it would be a cakewalk. With the new smCCR I may actually be going to all AL80's as well because of it, but then I have to wear lead :-(

About 3 weeks ago in Pompano.
 
Double bladder wings have declined in popularity because many divers concluded that they aren't any safer than single-bladder wings. Compared to a bag, the upside is that you can finish the dive with a normal amount of buoyancy and trim control rather than having to fuss with something that's an awkward shape and that is tending to pull you into an awkward orientation.

Some divers use two wings, instead of one wing with two bladders. Regardless, there are two possible ways to configure the two bladders. Each poses problems.

Method one. Each wing's power inflator is connected to an air supply

The problem here is that it is difficult to diagnose problems with a power inflator that is dribbling air into the wing. It is possible to have the secondary wing inflate slowly over the course of the dive and not realize that there is a problem until it is impossible to control ascent. Problems venting the wing must be solved quickly and the automatic (and usually correct) response is to try to exhaust trapped air from the primary wing. There is some added risk of a runaway ascent with this configuration that must be factored in when evaluating the safety benefit of being able to control a runaway descent due to a wing rupture.

Method two. Secondary wing power inflator isn't connected

The problem then is that it potentially takes longer to connect the power inflator to the secondary wing (or to inflate the wing orally) than it would to deploy a lift bag from a pocket or other reasonably accessible location. The usual approach is to inflate orally, but when a good deal of the wing capacity is in fact needed, this takes time and concentration. Once a lift bag starts to fill from a regulator that has the purge button depressed, it fills quickly.

Method one is dangerous.

If orally inflating a wing is a difficult chore to someone, they probably don't have the physical capacity to be technical diving.
 
Method one is dangerous.

If orally inflating a wing is a difficult chore to someone, they probably don't have the physical capacity to be technical diving.
It is definitely more of a challenge when using a CCR though.
 
Certainly, but that doesn't negate my point. If orally inflating a wing is something that a person can't do on any given dive, they're in over their head.
 
Everybody is in over their head. That’s why they need scuba. :rofl3:

Sorry...I just couldn’t help myself.
 
About 3 weeks ago in Pompano.

touche, was trying to prove the point that despite our best efforts, it is often not possible to dive a balanced rig due to the nature of cave diving. It is incredibly liberating when I do get to dive in the salty stuff, especially in singles with a balanced rig
 
touche, was trying to prove the point that despite our best efforts, it is often not possible to dive a balanced rig due to the nature of cave diving. It is incredibly liberating when I do get to dive in the salty stuff, especially in singles with a balanced rig

I took 15 or so cave divers to the ocean for some single tank diving in August. We all had a blast.
 
So what are you saying? In the same situation, getting a liftbag out from stowage, clipping it on, inflating it with an octo and maintaining a safe buoyant ascent - is easier and safer?


Excuse my incredulity. When the majority of divers struggle with DSMB deployment, shallow without any other task loading
As I recall, you dive where it's always warm.

Connecting an inflator hose is no small thing in thick gloves suitable for cold water.

When diving in cold water one uses a drysuite for redundant boyancy ...
 
https://www.shearwater.com/products/teric/

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