SMB as backup lift source.

[Graeme Fraser]

Unless I'm completely missing the point, as one of you guys already pointed out, surely the obvious solution is a dual bladder wing. I say that based on the fact that a) the OP does not want to purchase Ali doubles and b) he is only looking for redundancy in the event of primary bladder failure.

 

[Storker]

surely the obvious solution is a dual bladder wing

...or enough ditchable weight, or a drysuit

Given the OP's location, they probably don't want to wear an undersuit similar to the one I use, but a trilam with some thin thermals underneath could be a viable alternative. And with thin undergarments and a well-fitting suit, the issue of bubble management becomes small. Particularly if they run the suit tight.

 

[Graeme Fraser]

...or enough ditchable weight, or a drysuit

Given the OP's location, they probably don't want to wear an undersuit similar to the one I use, but a trilam with some thin thermals underneath could be a viable alternative. And with thin undergarments and a well-fitting suit, the issue of bubble management becomes small. Particularly if they run the suit tight.

Agreed. The optimal solution is definitely a balanced rig through Ali cylinders or DS but the OP has ruled those out. With the current perminantly overweight config I can't see how this can be achieved hence the compromise.

 

[CaveSloth]

Maybe I will buy aluminum tanks and add weight, either ditchable or non.

Balanced rig with a wetsuit pretty much mandates Aluminum tanks and extra weight doesn’t it?

 

[Ryan Mcshane]

Maybe I will buy aluminum tanks and add weight, either ditchable or non.

Balanced rig with a wetsuit pretty much mandates Aluminum tanks and extra weight doesn’t it?

Yup

 

[doctormike]

I'm not a DIR guy and I don't dive in a wetsuit, so maybe I haven't really thought about this as much as I should. But my reading of a "balanced rig" is that you can (1) be neutrally buoyant at your shallow stop without much gas in your tank(s), and (2) swim your rig up from depth without ditching weight or using your BC.

I don't think that there is a really good argument for ever ditching weights at depth - I suppose that if you had a very thick wetsuit and the combination of lost buoyancy from suit compression and the weight of gas in full tanks added up to more than you could swim up, then you would need to. But you would be better off not diving in that configuration. Ideally, if you had to bring a large amount of gas and dive in a thick wetsuit, you should be able to swim up enough to get some suit expansion, and make it to the surface without your wing (with an SMB as a redundant buoyancy).

The total amount of ballast that you need could be ditchable, non-ditchable, or some combination, but it doesn't change that analysis. The advantage of ditchable weight in my opinion would be for an injured or tired diver at the surface if they couldn't easily maintain positive buoyancy with their wing, or in a rescue situation on the surface.

The GUE website has this to say about double bladder wings: "Double wings are an invitation to a disaster - do not use them.". They do not elaborate further, and I haven't really heard a good reason why this is so. Maybe one of the GUE/DIR people can tell me. Again, I don't like diving heavy rigs in a wetsuit, so maybe it's better not to need a double wing, but if you do need redundant buoyancy, it seems to be as good an option as any.

 

[PfcAJ]

I'm not a DIR guy and I don't dive in a wetsuit, so maybe I haven't really thought about this as much as I should. But my reading of a "balanced rig" is that you can (1) be neutrally buoyant at your shallow stop without much gas in your tank(s), and (2) swim your rig up from depth without ditching weight or using your BC.

I don't think that there is a really good argument for ever ditching weights at depth - I suppose that if you had a very thick wetsuit and the combination of lost buoyancy from suit compression and the weight of gas in full tanks added up to more than you could swim up, then you would need to. But you would be better off not diving in that configuration. Ideally, if you had to bring a large amount of gas and dive in a thick wetsuit, you should be able to swim up enough to get some suit expansion, and make it to the surface without your wing (with an SMB as a redundant buoyancy).

The total amount of ballast that you need could be ditchable, non-ditchable, or some combination, but it doesn't change that analysis. The advantage of ditchable weight in my opinion would be for an injured or tired diver at the surface if they couldn't easily maintain positive buoyancy with their wing, or in a rescue situation on the surface.

The GUE website has this to say about double bladder wings: "Double wings are an invitation to a disaster - do not use them.". They do not elaborate further, and I haven't really heard a good reason why this is so. Maybe one of the GUE/DIR people can tell me. Again, I don't like diving heavy rigs in a wetsuit, so maybe it's better not to need a double wing, but if you do need redundant buoyancy, it seems to be as good an option as any.

Dual bladder wings are not an immediate solution.
Having both inflators connected would make it very difficult or determine which one would be auto inflating, so only one is hooked up at a time.

If that one fails, there’s no way you’ll be able to identify and inflate the other one to arrest your descent in a reasonable time frame. You’re still a lawn dart.

 

[doctormike]

Dual bladder wings are not an immediate solution.
Having both inflators connected would make it very difficult or determine which one would be auto inflating, so only one is hooked up at a time.

If that one fails, there’s no way you’ll be able to identify and inflate the other one to arrest your descent in a reasonable time frame. You’re still a lawn dart.

There is no reason to hook up the second inflator to a gas source. You just have it in case your primary bladder fails. Then you would inflate it by mouth.

And if you are concerned about sudden descent with a wing failure, how would a single bladder wing make that less of a problem?

I wasn't saying that if you have a double bladder wing you don't need to worry about being correctly weighted. I was saying that it was a better solution to the need for redundant buoyancy for a wetsuit diver than an SMB, which was the original question in this thread.

 

[PfcAJ]

There is no reason to hook up the second inflator to a gas source. You just have it in case your primary bladder fails. Then you would inflate it by mouth.

And if you are concerned about sudden descent with a wing failure, how would a single bladder wing make that less of a problem?

I wasn't saying that if you have a double bladder wing you don't need to worry about being correctly weighted. I was saying that it was a better solution to the need for redundant buoyancy for a wetsuit diver than an SMB, which was the original question in this thread.

There’s no way you can arrest a rapid descent caused by heavy steel doubles by orally inflating. Everything is working against you. Ears screaming. Gas compressing in the wing as you descend. Putting enough gas in the wing orally since its starting empty. Ain’t happening.

With light tanks, you could kick your clippers to stop your descent.

With a drysuit you can press the button to stop the descent.

 

[CaveSloth]

"Double wings are an invitation to a disaster" - GUE

Sure wish they would further explain that. How does the double wing, by itself, invite disaster? If it's not connected to anything and then furthermore if you have a balanced rig you can swim up, how does having a double bladder wing invite disaster?