Questions about Dual bladder wings

[TONY CHANEY]

Good point rlynch, but it is not a wet vs dry with steel tanks but a discussion of a backup bladder or not. I have Al tanks as well as steel tanks. OBTW, I really don't know how the 130's ever entered the discussion...I don't own any. Like all gear the backup bladder does need to be used and exercised which I do sometimes. The only drill I really do not perfer to do in cold water is mask off and replace. The problem of this thread was created by some trying to sway a new diver from buying and using a double bladder. No real reason was ever given just a true bashing of it.

---------- Post added February 8th, 2013 at 07:08 PM ----------

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?

Al tanks should never be overfilled!

 

[PfcAJ]

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.

You want to carry it that way so you aren't over-weighted with a wetsuit. With a drysuit you've got some more flexibility.

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?

Where are you getting these ideas? No one is overfilling al80s.

---------- Post added February 8th, 2013 at 11:41 PM ----------

and fwiw, if you get all those trailing stages layin right, you can scooter through the water at a pretty good clip, not much slower than without them. However, if your gear isn't set up right, you can forget it.

 

[ucfdiver]

No real reason was ever given just a true bashing of it.

Here's a first hand account on how dual bladder wing's don't really work
Twin January 20th

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

I've been there once or twice. Here's a video swimming two stages in the gallery, with HP130's and with a drysuit (the worst part of Ginnie). What's your point?
James In the Gallery on Vimeo
(Excuse my pocket opening, I caught it later in the dive)

 

[TONY CHANEY]

Here's a first hand account on how dual bladder wing's don't really work
Twin January 20th

That added nothing to the post other than silt. Here is what he said, "Upon exiting the hole from the cavern to OW, I had my pull dump stick and dump all of my air. When this occured, my feet were probally still at the edge of the rocks at the entrance hole. I was only about 3 ft above the bottom at the most. When I came out, I pulled to dump air for the ascent. The valve stuck, and before I could do ANYTHING, I hit the silt. I dive wet and do have a method for back up but BEING I WAS ON EXIT AND SO CLOSE TO THE BOTTOM, WHICH NO MATTER WHAT CANT BE CHANGED, THERE WAS NO TIME TO DO ANYTHING. No matter what you do, you have to exit the hole which requires you to be close to the bottom. I had no other issues on silting the hole until this happened.




I've been there once or twice. Here's a video swimming two stages in the gallery, with HP130's and with a drysuit (the worst part of Ginnie). What's your point?
James In the Gallery on Vimeo
(Excuse my pocket opening, I caught it later in the dive)

My point was pertaining to Danvolker stressing that we know very little about curent. Please go back and really read what he posted.

---------- Post added February 9th, 2013 at 12:54 AM ----------

OBTW James very cool video and you look like there is no flow at all but we know better.

 

[Abdullah]

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.

Where is the drag and clutter of a dual bladder?? Take a look at a DR Classic 60# dual bladder wing (no bungees) - You wouldn't know it was dual bladder unless the diver told you in the pre-dive. It's one corrigated hose behind the right arm. I think maybe you all are talking about different technology than I see in use.

Divers with a deco obligation and no redundant bouyancy swimming up towards the surface seems like an unnecessary PITA when they get to their stops. It's a my personal preference, but I prefer to be flat and calm in the water at my stops, not somewhat vertical and kicking to maintain my depth in the stop. The dual bladder allows me to comfortably complete my deco obligation, exactly as planned.

This thread started with a new tec student, who only dives wet in warm water, asking about dual bladders. So far, there hasn't been a good argument that a wet suit diver shouldn't go with a dual bladder wing.

 

[danvolker]

My point was pertaining to Danvolker stressing that we know very little about curent. Please go back and really read what he posted.

---------- Post added February 9th, 2013 at 12:54 AM ----------

OBTW James very cool video and you look like there is no flow at all but we know better.

Tony...I really think this is semantics, as their are really different levels of current forces depending on where you dive. I am not pushing this as a pissing contest, but because if you are geared for current, even when the current is small, you still move around in a way that I feel is better for diving--more enjoyable because you can make choices and do things the diver with too much drag can not do.

I don't have a video handy showing the Skycliffe on a "windy day", but here is one of the Jupiter Wrecks at only 100 feet deep---there is MUCH MORE CURRENT on the 200 foot and deeper wrecks and reefs, on days when it is cranking..... Watch from 7:36 in to this video, and see how the Jewfish must swim 45 degrees to the current, and how the divers need to be plastered to the bottom.... I shot this wearing dual 80's, and was slick enough to cover action that would not have been possible with the big floppy 4 tank set up.
[video=youtube_share;qeQp5aqy2_s]http://youtu.be/qeQp5aqy2_s?t=7m36s[/video]
Again, click ahead on the timeline to 7 minutes and 36 seconds, where we are exposed to the main current flow and out of the protection of structure.
Marine life on our deep reefs, particulalrly the 220 to 260 ledge, is amazing, but you must be slick or you will be a "leaf in the wind". I dive for marine life, not to swim deep into a wreck 1000 divers have already cleaned out of artifacts.

---------- Post added February 9th, 2013 at 09:22 AM ----------

Divers with a deco obligation and no redundant bouyancy swimming up towards the surface seems like an unnecessary PITA when they get to their stops. It's a my personal preference, but I prefer to be flat and calm in the water at my stops, not somewhat vertical and kicking to maintain my depth in the stop. The dual bladder allows me to comfortably complete my deco obligation, exactly as planned.

This thread started with a new tec student, who only dives wet in warm water, asking about dual bladders. So far, there hasn't been a good argument that a wet suit diver shouldn't go with a dual bladder wing.

The comfort level at the stops is the strongest point mentioned so far, and unrelated to use as an ELEVATOR, so this would be the point to address in future posts.
I can't say it means much to me, since if I do use a wetsuit for a tech dive, it is by Beuchat Camou spearfishing suit, and it has maybe 3 pounds of bouyancy to it....in other words, I need little in the way of actual bouyancy compensation----the reality is also, that on a 280 foot dive, the wetsuit offers almost no thermal protection during the deep portion of the dive---then again, it is hanging at all the deco stops that get's you cold, and they will work fine on the stops from 50 feet deep on up.

 

[TONY CHANEY]

Danvolker....looks like the current is really ripping down there and kinda like watching the diver being blown around have felt that before myself. Very nice video BTW. It seems that you are only one not laying on the bottom. I never said that you are not slick in the water. You just made the statement that more or less said that you can't be slick with big steel tanks. But, that's your opinion so cool. OBTW here is some cool flow Del Rio Cave Secrets on Vimeo

 

[danvolker]

Danvolker....looks like the current is really ripping down there and kinda like watching the diver being blown around have felt that before myself. Very nice video BTW. It seems that you are only one not laying on the bottom. I never said that you are not slick in the water. You just made the statement that more or less said that you can't be slick with big steel tanks. But, that's your opinion so cool. OBTW here is some cool flow Del Rio Cave Secrets on Vimeo

Wow....now that is a current in a Cave !! I wish it was a little closer to Palm Beach..
I would be stripped down to freedive profile, and pushing a "jacked" lp 120 ahead of me....However, I am not in to contorting into a cave restriction so tight my own body has to be inched through it--if it was that tight, it would remain unexplored

Has anyone made it through since the video?

 

[TONY CHANEY]

Wow....now that is a current in a Cave !! I wish it was a little closer to Palm Beach..
I would be stripped down to freedive profile, and pushing a "jacked" lp 120 ahead of me....However, I am not in to contorting into a cave restriction so tight my own body has to be inched through it--if it was that tight, it would remain unexplored

Has anyone made it through since the video?

As fas as I know...no. He made it pass the restriction and is opened up to a small room and the current was still ripping. there was another restriction but being low on gas...they exited the cave. This is all based on what was posted on CDF. If you like to have fun in high flow then go the Grand Ball room at Ginnie. Fin up to the metal grate hold on for a few minutes and then let go. The flow will blow you across the room.

 

[Abdullah]

You want to carry it that way so you aren't over-weighted with a wetsuit. With a drysuit you've got some more flexibility.

Considering your all aluminum solution to compensate for the lower volume of the AL80 twin set compared to HP100 steel tanks:

The back gas AL80s will start about 4 lb negative. Add the volume compensating stage and the tanks are about 6 lb negative at the start of the dive. The three AL80s will be about 10 lb positive when empty, which is a good planning volume for an OOA emergency. So, I’ll need 10 lb of lead to stay neutral during deco in an OOA emergency. Combine the 6 lb AL80 negative tank buoyancy with the 10 lb of lead and the all aluminum starting buoyancy is about 16 lb negative.

My HP100 twin set is about 20 lb negative at the start of the dive and about 5 lb negative at the end. I don’t need any additional weight on this rig. When my steel is heaviest in the water, it’s still only about 4 lbs heavier than the lead and three AL80s I’ll need for the all aluminum solution.

Whereas, the HP100s are every bit as streamlined in thewater as an AL80 twin set without that extra stage, the all aluminum solutionadds another stage which dramatically increases drag. Plus, the extra AL80 in your solution bringsit’s own set of additional failure points (another tank to manage, another reg, another gas switch, etc.). In an emergency, Hicks Law would favor the simpler steel configuration over the all aluminum solution.

Add the dual bladder wing (or dry suit for the cooler water divers), and I can comfortably maintain my deco stops in the event I have a problem with primary buouyancy.