DIR- Generic dual bladder wings...

[ABK]

Honestly, what failure point exists on a diver in a wetsuit with a dual bladder wing that doesn't exist on a diver in a drysuit with a single bladder wing? Same number of inflation valves. Same number of dump valves.

 

[PfcAJ]

It’s how the failures are managed that makes them different.

two inflators hooked up to one wing would make it nearly impossible to identify which is leaking. Depending on the severity of the leak, this could be very bad.

That being said, jumping in the water with heavy tanks and 1 active wing puts all your eggs in one basket. If the elbow fails, you’re a lawn dart headed straight for the bottom. No amount of oral inflation or fiddle****ing with the 2nd inflator is going to fix that quickly enough to stop you from doing a Russian Warship impersonation and sinking all the way to the bottom.

On to the good things about DIR with a drysuit and a wing:

A drysuit leak and a wing leak (hopefully) feel and sound different, giving you the option to respond quickly.

A wing failure with the drysuit gives you the option of hitting your drysuit inflator and arresting your descent.

 

[Alaskan Scuba Dude]

Honestly, what failure point exists on a diver in a wetsuit with a dual bladder wing that doesn't exist on a diver in a drysuit with a single bladder wing? Same number of inflation valves. Same number of dump valves.

None. Each bladder is connected to separate first stages. Essential for extreme depths where the water takes hold of you.


Don't forget to always carry two SMBs or one of each (lift bag) when diving deep.

 

[PfcAJ]

None. Each bladder is connected to separate first stages. Essential for extreme depths where the water takes hold of you.

It’s incredible. Every post you make is nonsense.

 

[Alaskan Scuba Dude]

It’s incredible. Every post you make is nonsense.

Humility: they realize that they don’t know everything, and that there may be more than one right way to do something. Their ego doesn’t get in the way of learning, doing or teaching.

Open mindedness: they never reject something just because it’s new or different, and they listen to other viewpoints. They don’t fear change and they’re not threatened by differing opinions.

Analytical: they accurately and realistically weigh the merits of a technology or procedures for themselves and never accept something just because it’s new or because someone else thinks it is better. They don’t let what they like, dislike or want to believe, influence their conclusions.

Competent: while they’re open to change and alternative ways to do things, their own methodologies are solid and they can demonstrate a rationale and realistic basis for each. They’re quietly confident about how they dive, and they don’t choose their methodologies based on looking cool or what someone else might think or say.

 

[doctormike]

I never understood the objection to a double bladder wing in the one situation where they are useful - doubles and a wetsuit (especially a thin one). I don't think that the second inflator needs to be connected at all. It's just a much easier backup buoyancy system than the alternative that I learned in AN/DP (using an SMB).

Not necessarily a lawn dart if you can get some gas in the second bladder quickly by oral inflation while finning up (I probably wouldn't want to do that on a black water dive with no bottom though).

The one time I appreciated that backup was in Truk, on OC doubles and wearing just a skin. I agree that a dry suit would have been safer from a buoyancy point of view, but it was pretty hot there...

 

[happy-diver]

 

[ABK]

It’s how the failures are managed that makes them different.

two inflators hooked up to one wing would make it nearly impossible to identify which is leaking. Depending on the severity of the leak, this could be very bad.

That being said, jumping in the water with heavy tanks and 1 active wing puts all your eggs in one basket. If the elbow fails, you’re a lawn dart headed straight for the bottom. No amount of oral inflation or fiddle****ing with the 2nd inflator is going to fix that quickly enough to stop you from doing a Russian Warship impersonation and sinking all the way to the bottom.

On to the good things about DIR with a drysuit and a wing:

A drysuit leak and a wing leak (hopefully) feel and sound different, giving you the option to respond quickly.

A wing failure with the drysuit gives you the option of hitting your drysuit inflator and arresting your descent.

That's a good explanation. I've been scratching my head over this. I can see where it would be very difficult to decide which wing is the leaking wing. Not a problem in a drysuit.

 

[Centrals]

Duel bladder wing is a lot heavier to carry otherwise I never had any issue with it.
As @doctormike suggested, there is no need to hook up the redundancy wing with the 2nd inflator.
Practice oral inflation and it is useful as I had found it out on two separated occasions.

 

[doctormike]

That's a good explanation. I've been scratching my head over this. I can see where it would be very difficult to decide which wing is the leaking wing. Not a problem in a drysuit.

I don’t understand that concern either. You hook up the left inflator to a second stage like usual. You use it like you usually do, using that bladder to offset however negative you are (a balanced rig hard to achieve in doubles and a thin exposure suit). In the VERY unusual case where THAT inflator/bladder system fails open from a leaky elbow or whatever, you just add gas to the backup bladder for buoyancy, using oral inflation of the right side.

Is the concern about simultaneous failure of both separate independent inflator/bladder systems? You aren’t supposed to be using both sides during the dive…