Questions about Dual bladder wings

[ucfdiver]

So, if it's too hot to wear a dry suit, how does a diver obtain the redundant bouyancy? The argument against dual bladder wings seems to be entirely predicated on the requirement to wear a dry suit, which is simply not a viable option in some climates. This seems to be a fundementally flawed concept.

HP130's hold 260cu ft of gas doubled.

AL80's hold around 155cu ft of gas doubled, or 230ish with a stage added.

You're going to have to work hard to give an example of a dive that can be done on HP130's that can't be done with AL80s. Either the 30ish cu ft gas difference won't matter, or the dive will be too long for a wetsuit.

Once we get out of hypothetical worlds and start focusing on real life dive, these "flaws" prove to not matter.

 

[rjack321]

We don't use AL80s for 280ft (or even 180ft) dives up here. The lead to sink the tanks and drysuit is annoying. A few people might, but its still annoying to carry lead to sink bouyant tanks when you could bring less bouyant slightly larger steel tanks instead and need less lead. Don't know anyone diving wet (or lycra...) or dual bladder wings either.

 

[bakodiver391]

This argument has been kicked around the other boards as well and probably will continue to be. For myself, I dive 150-180ft in wetsuit, steel 85's, and a 50cu pony with runtimes around 2 hours+, and yes, I use a double bladder. The tanks I use are the best tools to get the job done, period, and an argument that I should use less than optimal tanks for the sake of some notion that I should swim my tanks up and hold stops for 1 1/2 hours is flaky, to say the least. I also carry two bags, and shoot them often, so I know I can rely on 4 separate buoyancy systems to get me through my deco. The bladder is the best tool to hold stops, so why not have a redundant one? In cave and penetration diving, it was recognized that light failure could be life threatening, so everyone carries 3 lights. Why change the formula for buoyancy? Personally, I would never take a course with an instructor who thinks otherwise.

 

[Abdullah]

HP130's hold 260cu ft of gas doubled.

AL80's hold around 155cu ft of gas doubled, or 230ish with a stage added.

You're going to have to work hard to give an example of a dive that can be done on HP130's that can't be done with AL80s. Either the 30ish cu ft gas difference won't matter, or the dive will be too long for a wetsuit.

Once we get out of hypothetical worlds and start focusing on real life dive, these "flaws" prove to not matter.

Why would I want to drag an extra AL80 stage through the water if I can carry that volume of gas, and then some, streamlined on my back? It seems like you want to de-optimize the gas storage in order to maintain a less efficient standardized configuration.

I've never been time limited on a dive by my wetsuit, but I am routinely limited by the volume of gas I can carry.

 

[TONY CHANEY]

HP130's hold 260cu ft of gas doubled.

AL80's hold around 155cu ft of gas doubled, or 230ish with a stage added.

You're going to have to work hard to give an example of a dive that can be done on HP130's that can't be done with AL80s. Either the 30ish cu ft gas difference won't matter, or the dive will be too long for a wetsuit.

Once we get out of hypothetical worlds and start focusing on real life dive, these "flaws" prove to not matter.

Why not just compare apples to apples? Why does it have to be 130's compared to 80's with a stage? So 130's give you 260 cu ft and 80's give you 154 cu ft so the real difference is 106 cu ft. 106 cu ft is a hell of a lot of gas! Please don't fudge the numbers by only adding the stage to the 80's in order to make it look closer.

---------- Post added February 8th, 2013 at 02:08 PM ----------

Why would I want to drag an extra AL80 stage through the water if I can carry that volume of gas, and then some, streamlined on my back? It seems like you want to de-optimize the gas storage in order to maintain a less efficient standardized configuration.

I've never been time limited on a dive by my wetsuit, but I am routinely limited by the volume of gas I can carry.

I'm with you....I have turned more dives on 3rds or low on gas than I have coldness.

---------- Post added February 8th, 2013 at 02:34 PM ----------

So far we have discussed this issue indepth but in order to try and get it back on coarse...has anyone given a valid reason why a double bladder is bad? So far no! OBTW, the elevator post is not valid because you should use a backup wing just like you use any wing. I think it was much easier to pick the dual bladder apart when it was about only OMS but look around lately and you will see several companies making them. i.e. ScubaPro, Hollis, Zeagle, Dive Rite, Deep Outdoors, etc.

 

[danvolker]

Why not just compare apples to apples? Why does it have to be 130's compared to 80's with a stage? So 130's give you 260 cu ft and 80's give you 154 cu ft so the real difference is 106 cu ft. 106 cu ft is a hell of a lot of gas! Please don't fudge the numbers by only adding the stage to the 80's in order to make it look closer.

---------- Post added February 8th, 2013 at 02:08 PM ----------



I'm with you....I have turned more dives on 3rds or low on gas than I have coldness.

---------- Post added February 8th, 2013 at 02:34 PM ----------

So far we have discussed this issue indepth but in order to try and get it back on coarse...has anyone given a valid reason why a double bladder is bad? So far no! OBTW, the elevator post is not valid because you should use a backup wing just like you use any wing. I think it was much easier to pick the dual bladder apart when it was about only OMS but look around lately and you will see several companies making them. i.e. ScubaPro, Hollis, Zeagle, Dive Rite, Deep Outdoors, etc.

Regarding the elevator.... With a wing failure, you should not need the wing. You don't need redundancy for something you don't need. Trim may be off, but this is not worth the trade off in drag and clutter of the dual bladder wing.
Divers should be swimming up toward the surface, not "ELEVATORING" UP.

It could be just that we see different MAJOR ISSUES here in South Florida, than you guys see in the North East...or off Carolina.... For us, big currents bring massive schools of marine life over shipwrecks and deep reefs--National Geo type stuff...so we "like" the big currents.....But there is a "cost" to it, and that is moving from point A to B underwater, when currents effect you....For us, we really have to be "slick" in the water, and for me that also means no stage, just back gas, if I can get a way with it.
For me, penetrating deep into a wreck and/or crawling around and digging in the mud, is not the point of most deep dives...I am there for the Nat Geo moments, to see the life.
If I was treasure diving, or salvage diving, maybe I would be more in-tune with you guys with your desire to do massive bottom times with huge gas volumes.
I am happy with 25 minutes at up to 280, and all I need for this is backgas and a 30 cu ft 100% O2 stage ( very low drag--almost like nothing is there). For the stuff shallow enough to remain normoxic, then just back gas with no stages....Waayy Better!!! We get to move like we belong underwater, not like the tech guys I see all puffed up with 4 or 5 tanks on them, the stages perpendicular to current flow and slowing the slow divers down, even further.

 

[TONY CHANEY]

"Regarding the elevator.... With a wing failure, you should not need the wing. You don't need redundancy for something you don't need. Trim may be off, but this is not worth the trade off in drag and clutter of the dual bladder wing.
Divers should be swimming up toward the surface, not "ELEVATORING" UP."

So what you are saying is that you really don't need a wing at all. Just joking but here is the elevator BS again. Why in the heck can't you understand that just because you have a double bladder does not mean you can't swim up? So another worthless point that adds nothing to this discussion.

"But there is a "cost" to it, and that is moving from point A to B underwater, when currents effect you....For us, we really have to be "slick" in the water, and for me that also means no stage, just back gas, if I can get a way with it."

Ever dived Ginnie springs or Little River? Please tell us more about us not understanding not only current but consistant high flow.

"For me, penetrating deep into a wreck and/or crawling around and digging in the mud, is not the point of most deep dives...I am there for the Nat Geo moments, to see the life."

I agree because touching the bottom is not what we perfer to do ing the caves and is really looked down upon.

"We get to move like we belong underwater, not like the tech guys I see all puffed up with 4 or 5 tanks on them, the stages perpendicular to current flow and slowing the slow divers down, even further."

So you mean tech guys like this WKPP Update, Spring 2000 | Global Underwater Explorers you are right

 

[danvolker]

"Regarding the elevator.... Why in the heck can't you understand that just because you have a double bladder does not mean you can't swim up? So another worthless point that adds nothing to this discussion.

If you don't need the double bladder to swim up, then why have it? Why bring something you would never need?

"But there is a "cost" to it, and that is moving from point A to B underwater, when currents effect you....For us, we really have to be "slick" in the water, and for me that also means no stage, just back gas, if I can get a way with it."

Ever dived Ginnie springs or Little River? Please tell us more about us not understanding not only current but consistant high flow.

If guys wearing 4 monster tanks, some perpendicular, and with double bladder wings, can "swim" against a current, it is not much of a current. Period.
Take the same diver with the 4 monster tanks , stages perpendicular, double bladder and other drag issues that go with this mindset---put them on a fast Scooter....SEE what happens to the perpendicular hanging tanks and the speed and ease of control of the scooter...Or, just dive the Skycliffe off Boynton some time on a normal day( typical high current wreck--only about 225 feet deep) and try moving against the current.

"We get to move like we belong underwater, not like the tech guys I see all puffed up with 4 or 5 tanks on them, the stages perpendicular to current flow and slowing the slow divers down, even further."

So you mean tech guys like this WKPP Update, Spring 2000 | Global Underwater Explorers you are right

That looks like someone shuttling tanks to a tank drop for an exploration push....in a team setting, you have divers that set stage bottles at various points along the length of a long exploration push( I am sure you know this--I just mention this for non-cave divers that could read this). This would be the mission, not having fun, and not being slick--the mission is to be a Tractor Trailer Truck for some team mates ***None of these divers EVER used dual bladder wings, even shuttling 6 tanks.

 

[rlynch]

In reality you guys are fighting a wet vs dry with steel tanks battle.

Lots of folks have already died doing this. For lots of reasons mostly bc they thought they were "safe & covered" turns out they Weren't.
People still die in drysuits whom are over weighted but the complexity of the solution is less, which gives it the advantage. Basic common sense dictates a solution that can provide lift at depth (after a certain point wetsuits don't) is a good thing when diving with tanks that are difficult to swim up from beyond the zone of wetsuit buoyancy. Or use lighter tanks and add gas via stages which can be jettisoned if needed.
To me this is the same argument that people use for doing all buoyancy with a drysuit, which is another bad idea in the over all scheme of things. Drysuits vent like crap vs a wing.
To me I see the main issue with a dual wing as "training and practice" most never do anything with the second inflator in a real life env. Where as I am constantly adjusting wing suit and stages/deco bottles. Something happens I don't need to think about where I put my second inflator, is it hooked up, what do I need to do etc.
not going to change any minds here, but look at the pros and cons from a realistic operational pov. If you use it once a year, your relearning it

 

[dumpsterDiver]

Dan you always seem to leave out the part about drastically overfilling those little aluminum 80 tanks...Seems like that should be mentioned...Is that standard GUE protocol for the dives you are talking about?