Need Help - Dual Bladder BC, which ones and where to buy

[Belmont]

Belmont - Im confused , where the tanks extra big? Surely he would have checked when he bought the rig that a set of tanks would fit on with the current bolts? I remember helping a mate set up his bands when he first bought them and we sat in his living room making sure everything fitted before even getting the tanks filled!

He was using rental tanks, standard 80 aluminum with standard bands. Different ones every day.

 

[japan-diver]

Just a few things- have seen a torn double bladder on a wreck - went through both bladders so the dual bladder didn't save anything.

I teach and dive in the tropics and when doing deco a drysuit with light undergarments is definitely the way to go. For short deco dives with warm water 165ft or so we can get by with a wetsuit but then there is no reason for heavy steel tanks as double aluminum 80's or even 63's are plenty at that depth with limited exposures.

 

[danvolker]

A double bladder can be useful when you are diving wet, with steels and stages. You are not going to be able to swim it and by the time you get your lift bag inflated you could be standing on the bottom.

I am interested, who has seen a dual bladder failure? I hear people say all the time, what punctures one will puncture the other, but have yet to have met anyone who has seen a dual bladder failure.

I have to ask....why in the world would a diver CHOOSE to be this negative on the bottom? It is going to happen on every single deep dive--you will always have to dump enormous amounts of air into ridiculously large wings, creating a massive frontal cross section as you try to propel yourself forward.
So you have this horribly overweighted diver, with wings full of air to compensate, finning away furiously, moving at a snail's pace along the bottom. The gas in the tanks gets sucked up quickly by all the inefficient propulsion, and next thing you know, the dive shop is having to sell these divers bigger tanks, like double 130s so that they can have more bottom time.....then , as they move even more slowly, and weigh even more on the bottom, still more solutions and gear purchases are needed.....hmmnn... I wonder if this is a "dive industry solution??? "....


There are drysuits that are around $1000 ....not so much more money than a wetsuit.....the why of this whole wetsuit and steels thing just escapes me.

 

[frogdrvr]

I agree that steels and wetsuits are not the ideal choice. If you are diver that travels the not so developed world sometimes that is what is available. I do want to focus on the dry suit issue a bit though.

To me there is only one good reason to use a drysuit on a dive and that is you need the thermal protection. Otherwise a wetsuit is less complex, if it tears no big deal. If you are diving a helium mix there is no need to carry a seperate bottle to fill it. Etc

I have now heard of one double wing bladder puncture, but how many people do you know that have torn their drysuit of have had a leaky drysuit on a dive? How much air can you add to your drysuit without it leaking around the neck?

A proper double bladder does not have overlapping bladders. Ie a puncture of one bladder does not lead to a puncture of both unless you run into a sword below. The bladders are offset in quadrants normally. So one bladder is upper right and lower left with the other being just the opposite. Each bladder has its own hose and either can be manually inflated. Bottom line is it is a redundant system.

 

[danvolker]

I agree that steels and wetsuits are not the ideal choice. If you are diver that travels the not so developed world sometimes that is what is available. I do want to focus on the dry suit issue a bit though.

To me there is only one good reason to use a drysuit on a dive and that is you need the thermal protection. Otherwise a wetsuit is less complex, if it tears no big deal. If you are diving a helium mix there is no need to carry a seperate bottle to fill it. Etc

I will agree that if there is no real chance of a cold thermocline, and the water is really warm or hot all the way to the bottom, then a LYCRA or similar material skin suit ( zero bouyancy effects) would be the way to go... I have done this myself many times in the distant past--on warm summer months in Florida....problem here is that you "can" have a huge inversion layer come in, where surface temps in the low 80's goes to low 60's at 200 feet...so when the skin suit diver hits the thermocline, they have no choice but to abort the dive.....which is a very annoying event....after a few of these events, a dry suit looks really good for deep dives

The wet suit is still categorically a poor choice for any deep dive. You NEVER want to plan on that large a bouyancy swing---and having to fill up a huge wing on purpose with this much air on every deep dive.

 

[udtfire]

This is my opinion the Dual bladder is Needed if you Have Tanks to Heavy (steel) to Swim up Like D-130-s and in a cave I Don't think you Would use a SmB so for Me its simple if you lost your Bladder would you be able to Hold Trim swim it up and get yourself Home If Not you Need a Dual Bladder the Motto is Two is one and one is None your safety is up to you. so Dive safe See u in the water. I Like the HOG Bladder.

 

[japan-diver]

A proper double bladder does not have overlapping bladders. Ie a puncture of one bladder does not lead to a puncture of both unless you run into a sword below. The bladders are offset in quadrants normally. So one bladder is upper right and lower left with the other being just the opposite. Each bladder has its own hose and either can be manually inflated. Bottom line is it is a redundant system.

Which double bladder is designed like this? I have sold just about every brand of wing made and never heard or seen of a double bladder designed like you describe. The tear was caused while going though a very tight spot on a wreck, rusted, jagged metal can be sharper than any sword.

 

[cool_hardware52]

A proper double bladder does not have overlapping bladders. Ie a puncture of one bladder does not lead to a puncture of both unless you run into a sword below. The bladders are offset in quadrants normally. So one bladder is upper right and lower left with the other being just the opposite. Each bladder has its own hose and either can be manually inflated. Bottom line is it is a redundant system.

Can you name one currently sold that's built this way.

*Every* redundant bladder wing I've ever seen was essentially one outer shell (sewn bag) stuffed with two *Identical* bladders, one facing "front" and the other flipped over.

That why the "second" corrugated hose is on the diver's side of the wing and the second OPV is on the lower right, tank side.

This is done so the *exact same* bladder can be used. Bladder dies aren't cheap, and stocking a bunch of special parts for a low volume product just isn't very appealing to most wing vendors.

Tobin

 

[frogdrvr]

My apologies. I could not find a commercially available wing designed as I described above.

To the argument to avoid wetsuits because of their differing bouyancy charachteristics dependent on depth, no pun intended the argument does not hold water.

A drysuit adds much more complexity to a dive than a dual bladder BC. Unless you need the extra thermal protection a drysuit brings why would you add it in?

"I will agree that if there is no real chance of a cold thermocline, and the water is really warm or hot all the way to the bottom, then a LYCRA or similar material skin suit ( zero bouyancy effects) would be the way to go... I have done this myself many times in the distant past"

I am curious Dan, on the dive profiles you described above, what did you use for redundant lift? A bag?

 

[frogdrvr]

Apeks Products

57# Vertex Extreme Dual Bladder Dual Inflator : OxyCheq - DiveOps, Analyzers and Scuba Diving Equipment

Posted a couple of nice commercially available dual bladder wings, to try and help answer the original question.