double bladder

[Mako Mark]

What about overactive bladders?

dual bladders are only needed while diving wet. Its called cold water diuresis Kev, dont you know anything....????

 

[Reinoud]

What I could never understand is why people are against the double bladders, its really no different than a single bladder, the argument for the run away ascent when the inflator sticks, well folks there is a REALLY EASY fix for that, only hook up one inflator and if you have to switch to a backup, use it orally, I don't think my lungs will stick open and over fill my second bladder causing a rapid ascent.

As for points of failure if I manually use my second inflator, how many failure points have I added? none really, if I'm swimming along and the seat on my backup bladder oral inflator hose fails, big deal.

How do you use your read dump valve when using a double bladder? Or do you have several and do you have to unlearn your normal way of dumping air while ascending on you 'alternative bladder'? (in other words: do you have to perform a basic task in a different way when you are in trouble?)

 

[Lane Zimmer]

Precisely, why are they such a bad thing? becuase in the event the inflator failed it would lead to a runaway ascent. Same can potentially happen on a dry suit. the difference, as i can see it, is that with a double bladder wing, you may not know which inflator had failed. So if the hose is disconnected, or isolated by means of a valve, until it is needed what is the problem?

+35 Degree C deck temperature and 28DegreeC water temp does not make a dry suit a very inviting prospect, unless very long hangs were envisaged.

I still think the 100lb wings are an abomination

If a failed inflator caused a runaway ascent, maybe that person should spend some more time in the pool.

Granted, warm temperatures do not make drysiuts very appealing. If it's that warm, use a different setup. It is not required that you use steel doubles. A wetsuit and double AL 80's make a great warm water setup.

DB wings serve no purpose and solve problems that shouldn't exist in the first place.

 

[Diver0001]

Precisely, why are they such a bad thing?

The DIR answer to this would be that double-bladder wings add extra complexity (and maybe extra potential failure points) without really solving any problems. If you need redundant buoyancy then the method to achieve that with the least complexity is to use a drysuit. If you can't use a drysuit then the answer is to remove the need for redundant buoyancy by balancing the rig, again the least complex answer.

There are obviously other configurations imaginable whereby the rig is not balanced and the drysuit isn't really an option. DIR is uncompromising about things like this and I would think that *if* you are going DIR then such configurations would be considered not fit for purpose and therefore undivable.

I have another question for the DIR guru's. IANTD teaches using the decobuoy for redundant buoyancy. What is the DIR stance on that? and on a related note does the GUE teach this too?

R..

 

[jonnythan]

How do you use your read dump valve when using a double bladder? Or do you have several and do you have to unlearn your normal way of dumping air while ascending on you 'alternative bladder'? (in other words: do you have to perform a basic task in a different way when you are in trouble?)

Using the right side inflator and dump valve is definitely doing "a basic task in a different way when you are in trouble."

As opposed to, say, cranking down your dyrsuit dump valve and inflating that sucker with 6 gallons of air. That's a basic task in the normal way, right?

 

[FIXXERVI6]

How do you use your read dump valve when using a double bladder? Or do you have several and do you have to unlearn your normal way of dumping air while ascending on you 'alternative bladder'? (in other words: do you have to perform a basic task in a different way when you are in trouble?)

read dump? rear dump?, my second bladder has a rear dump so I can continue to dump in a head down possition, or pull my backup inflator over my shoulder (I can breath in it under for a QUICK deploy and inflation when needed) and have a dump like on my left.

 

[Reinoud]

Using the right side inflator and dump valve is definitely doing "a basic task in a different way when you are in trouble."

As opposed to, say, cranking down your dyrsuit dump valve and inflating that sucker with 6 gallons of air. That's a basic task in the normal way, right?

Why do you need extra air in your drysuit? You have a balanced rig right? so you can just swim up

 

[jonnythan]

Why do you need extra air in your drysuit? You have a balanced rig right? so you can just swim up

Precisely how many pounds of carried gas can you swim up?

 

[Lane Zimmer]

 

[StSomewhere]

I have another question for the DIR guru's. IANTD teaches using the decobuoy for redundant buoyancy. What is the DIR stance on that? and on a related note does the GUE teach this too?

Feel free to correct me if I'm misunderstanding this. I haven't taken the IANTD Adv EANx (yet), but if I understand the standards and procedures for Adv EANx you have to deploy the lift bag as an ascent platform (ascent line). The tech course does have you demonstrate using a lift bag as an emergency BCD, but only to demonstrate that its not suitable as a redundant BCD. http://www.iantd.com/standards/IANTD_Standards_2003.pdf

Sort of back on topic, then is using a single E7-100 with an aluminum bp and a 3mm suit not DIR? That should be only 10 lbs negative with a full tank, minus the wetsuit buoyancy, correct? How much leeway is there in terms of negative buoyancy for a balanced rig and the weight of gas in the full tank?