Questions about Dual bladder wings

[danvolker]

Why would you wear the dry suit if it is hot? As a South Florida diver, the only way I put mine on in summer, is if I am going to do a tech dive, and the probability is that the water will be in the 60's or below at depth. Because we have inversions here often, the tech dive warrants it, but for water over 76 degrees, there is no way in the world I would wear a dry suit---they are a pain to have to mess around with, and all the huge drag they cause slows me down so much in the water, I see it as very limiting. Just not as limiting as hypothermia

So if the water was warm, the deep dive would be with Lycra or other tech fabric, with no bouyancy charicteristics, and then with double al 80's ( and an aluminum stage if needed)

 

[TONY CHANEY]

Sure... here is the "official" explanation:

" By George Irvine

In short... balanced rig is not using "double steel 120's plus a steel 45 for deco at 170fsw", unless paired with redundant buoyancy in the guise of a drysuit. Simple really...

You just said what I was saying, "UNLESS PAIRED WITH REDUNDANT..."

I believe the issue of run-away ascent is very realistic - although I cannot claim knowledge of a specific accident report to substantiate that credible concern.

You could have stoppped with that. You have no known knowledge but...

 

[danvolker]

Sure... here is the "official" explanation:

"By George Irvine

In short... balanced rig is not using "double steel 120's plus a steel 45 for deco at 170fsw", unless paired with redundant buoyancy in the guise of a drysuit. Simple really...

You just said what I was saying, "UNLESS PAIRED WITH REDUNDANT..."

I believe the issue of run-away ascent is very realistic - although I cannot claim knowledge of a specific accident report to substantiate that credible concern.

You could have stoppped with that. You have no known knowledge but...

George was very clear about the drysuit being suitable, and that the BC would never be the solution for tanks so heavy that you could not swim them up. He was also very clear that in ocean, double 80's are the way to go, not heavy steels. Because Drysuits require so much weight, using them meant some tank combinations that were heavier than 80's.....but nothing so heavy that a dual bladder wing would be considered.

It might be worth revisiting a key difference between the drysuit and the dual wing bladder.... The drysuit is forced on you for thermal protection.....since you are using it, you have a contant use of the bouyancy control in a drysuit, this constant as you descend or ascend...on every dive you make. The diver should have great skill with a drysuit and bouyancy control, long before they get to tech diving.

The dual bladder wing on the other hand, is chosen solely to be an ELEVATOR...actually a redundant elevator. Something that has --as a purpose, lifting a diver from bottom to surface, with a lift far greater than the diver is capable of by swimming propulsion, and in fact, is required because the diver WOULD BE UNABLE to swim themselves to the surface, given the foolishly heavy tanks that this ELEVATOR concept in a BC allows. The Elevator operation is dangerous on many levels, and should really have it's own thread.

George and all of WKPP, and all of DIR is against this, conceptually. It is not something we can stop people from using, but we can certainly demonstrate why we like the Balanced Rig concept much more.

 

[Abdullah]

George was very clear about the drysuit being suitable, and that the BC would never be the solution for tanks so heavy that you could not swim them up. He was also very clear that in ocean, double 80's are the way to go, not heavy steels. Because Drysuits require so much weight, using them meant some tank combinations that were heavier than 80's.....but nothing so heavy that a dual bladder wing would be considered.

It might be worth revisiting a key difference between the drysuit and the dual wing bladder.... The drysuit is forced on you for thermal protection.....since you are using it, you have a contant use of the bouyancy control in a drysuit, this constant as you descend or ascend...on every dive you make. The diver should have great skill with a drysuit and bouyancy control, long before they get to tech diving.

The dual bladder wing on the other hand, is chosen solely to be an ELEVATOR...actually a redundant elevator. Something that has --as a purpose, lifting a diver from bottom to surface, with a lift far greater than the diver is capable of by swimming propulsion, and in fact, is required because the diver WOULD BE UNABLE to swim themselves to the surface, given the foolishly heavy tanks that this ELEVATOR concept in a BC allows. The Elevator operation is dangerous on many levels, and should really have it's own thread.

George and all of WKPP, and all of DIR is against this, conceptually. It is not something we can stop people from using, but we can certainly demonstrate why we like the Balanced Rig concept much more.

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.

 

[danvolker]

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.

Abdullah, the deal is, for deep ocean tech dives, you use double Aluminums, or something with similar bouyancy charicteristics.
I think part of the issue is PADI Tech , certifying divers with such bad SAC Rates, that they need twice the gas of a diver doing 280 foot deep dives with double 80's. The solution is not bigger/heavier tanks. The solution is either shorter dives, or waiting till SAC Rates get better, before doing the dives where these monster tanks are being misused.
Another way to make the dive safer with dual 80's( can incude a staged al too) is to use a scooter, which will drastically improve SAC Rates for many tech divers. So the money spent on all the wrong tanks and extra regs, can instead go to a scooter

 

[rlynch]

A trilam drysuit is perfectly fine in hot climates, you just need less insulation. Really to need to match insulation to the diving env. Rather than the topside temp, to account for temp at depth.

Sure it's hot above but so's a wetsuit on a hot day.

 

[TONY CHANEY]

Abdullah, the deal is, for deep ocean tech dives, you use double Aluminums, or something with similar bouyancy charicteristics.

He also said you should use steel tanks for caving...which I do.

I think part of the issue is PADI Tech , certifying divers with such bad SAC Rates, that they need twice the gas of a diver doing 280 foot deep dives with double 80's. The solution is not bigger/heavier tanks. The solution is either shorter dives, or waiting till SAC Rates get better, before doing the dives where these monster tanks are being misused.

He made his post in the 1990's befoe PADI fully started their Tech course and who the heck said that PADI is only cartifying divers with bad SAC rates?

Another way to make the dive safer with dual 80's( can incude a staged al too) is to use a scooter, which will drastically improve SAC Rates for many tech divers. So the money spent on all the wrong tanks and extra regs, can instead go to a scooter

I'll agree that using a scooter helps with you SAC rate until it goes south. But there is no way you are going to find a good scooter for the price of a set of larger tanks. If you do please let me know. OBTW, WKPP was done on RB's.

On another thought why is a backup BC viewed as an "elevator" but a regular BC is not? You treat them the same.

But you know, I really don't care how you dive...just answer the OP's question. There is nothing that has been stated that there is a problem with double bladders. To each is their own and we can all have fun at a great sport.

 

[danvolker]

To each their own got alot of Divers killed in the 90's.....the whole personal preference thing...
WKPP did a huge amount of deep ocean which went to This issue....using aluminums....also, there are far more wkpp man hours on tanks than with rebreathers.
Much thought has gone into Training Avency ideas on how a BC should be used...few would suggest that a new diver should be taught to do an ascent from
the bottom by using the BC as an Elevator....

 

[LiteHedded]

I'll agree that using a scooter helps with you SAC rate until it goes south. But there is no way you are going to find a good scooter for the price of a set of larger tanks. If you do please let me know. OBTW, WKPP was done on RB's.

On another thought why is a backup BC viewed as an "elevator" but a regular BC is not? You treat them the same.

But you know, I really don't care how you dive...just answer the OP's question. There is nothing that has been stated that there is a problem with double bladders. To each is their own and we can all have fun at a great sport.

ORLY?

Summer 1996: WKPP explorers George Irvine, Jarrod Jablonski and Brent Scarabin reached, with open circuit scuba, 10,000 feet/3,048 meters from the Wakulla Springs cave entrance, maintaining an average depth of 285 feet/87 meters.

November 30, 1996: The WKPP team of Rick Sankey and Brent Scarabin set a world penetration record of 14,104 feet/4,299 meters in the Chips Hole siphon in northern Wakulla County, Florida. The team added 3,165 feet/965 meters of line to the legendary Sheck Exley's great effort of 1989.

 

[Trace Malinowski]

The dual bladder wing on the other hand, is chosen solely to be an ELEVATOR...actually a redundant elevator. Something that has --as a purpose, lifting a diver from bottom to surface, with a lift far greater than the diver is capable of by swimming propulsion, and in fact, is required because the diver WOULD BE UNABLE to swim themselves to the surface, given the foolishly heavy tanks that this ELEVATOR concept in a BC allows. The Elevator operation is dangerous on many levels, and should really have it's own thread.

George and all of WKPP, and all of DIR is against this, conceptually. It is not something we can stop people from using, but we can certainly demonstrate why we like the Balanced Rig concept much more.

Dan,

The purpose of a dual bladder wing isn't supposed to be an elevator nor is it supposed to be an excuse to dive cylinders that a diver is not able to swim up. The purpose of the dual bladder is to simply be a redundant buoyancy source. A diver still needs to choose cylinder sizes wisely.

The BC is the most misused scuba diving tool. Divers learn to use it, inappropriately, as an elevator.

During the diving death and murder investigation of the woman killed while diving on her honeymoon in Australia, Nancy Grace had Capt. Steve Bielenda on her show to explain how scuba gear works. Nancy said that she herself was a certified PADI open water diver and she couldn't understand why the victim just didn't hit "the button that saves" on her BCD.