Boston Breakwater
"Outlaw." Solo Diver
Hello. I didn't want to curtail my O.P. in the cave diving...Wet/Dry/Pros/Cons.
This is something, I'm highly interested in.
So, as a self proclaimed compressed air junkie...my research begins.
Thanks to all.
Cheers.
Questions about Dual bladder wings
Trace MalinowskiCave Instructor
# of Dives: 5,000 - ∞
Location: Alexandria Bay, NY
Before I learned to use a dual lift wing properly I believed a lot of the rhetoric. There are pros and cons to wearing a dual bladder wing just as there are pros and cons to wearing a drysuit and a single lift wing. The pro of a dual bladder wing is that you have redundant lift in a device that is designed to provide lift. Drysuits are not optimal for redundant lift - especially once the diver reaches the surface and is in a vertical position. Drysuits will often burp gas out of the neck seal. Try an experiment and tread water in heavy steel tanks in open water without the wing inflation. Only use drysuit inflation. What happens? Does your suit burp gas? Do you find yourself struggling a bit? A lot? This will depend upon the diver, what size tanks he is using, and the fit of the neck seal.
I've seen a drysuit fail to suspend a student wearing a DUI TLS-350 when the elbow came off the wing's corrugated inflator hose. The team provided the redundant lift needed by assisting the diver to shore not far away. Had this happened in the ocean awaiting pick-up by boat, the diver whose wing lost gas could have panicked or the team may have decided to ditch the entire scuba rig. Some divers have little problem treading water in high capacity steel tanks without inflation in either the suit or the wing. Others cannot. One's physical prowess and diving skill may also come into play when deciding on a single lift wing vs. a dual lift wing.
Diving environment is also a factor. Are you diving in warm open ocean or in caves? Most caves allow you to push, pull, and crawl your way out of with a buoyancy failure and many will allow you to stand up in shallow water at some point near the exit. In cold open water, you are probably already wearing a drysuit. A drysuit plus a dual bladder wing is needless drag. If you are wearing a drysuit then a drysuit and a single wing is a better bet than a dual lift. Ascent is another issue. If you somehow got gas in the second bladder at depth, you'd now be managing 3 devices in which gas would be expanding during ascent - wing 1, wing 2, and drysuit. Not recommended!
How would gas get in the wing? Well, it shouldn't be from an LP auto-inflator hose. DO NOT ... again, DO NOT connect the redundant inflator/wing to an LP auto-inflation hose! Leave the redundant wing as oral inflate only. Before the dive, fully orally inflate the redundant wing and make sure it is working. Make sure the OPV works just like a single wing. Then dump as much gas as you can and inflate your primary wing all the way with the auto-inflator. Dump the rest of the gas from the redundant wing as you do this. The redundant bladder should now be collapsed.
While it is probably true that most wing tears may come in two's OPV failures and corrugated hose failures will normally only happen to one side or another. I will often remove OPV's in classes and most students never notice. Lost corrugated hoses are a different story. If an OPV fails or if the wing tears near the bottom a diver can drop the trim angle to hold gas in the upper part of a wing maintaining lift. A lost corrugated hose or tear on the top of a wing will be far more difficult to manage.
A couple weeks ago my Halcyon Evolve with 40 lb. lift failed while cave diving at Ginnie thanks to the OPV. I was returning via the Lips Bypass and got stuck. After wiggling free I thought a post or manifold had started to leak because I could hear bubbling above me in the tight space. I flow checked, but couldn't determine the source. It wasn't until I got into bigger passage that I noticed my buoyancy was being lost. As I added gas it was just streaming out the OPV. I monkeyed around with it and then it held. Even with a single wing you can find yourself taking a bit of time to diagnose a wing problem. A dual bladder will complicate diagnosis. For this reason, if you need redundant lift you want to try to avoid adding gas at depth or too much gas. If buoyancy is lost at depth you should attempt to control the ascent with whatever gas you save or add in the primary wing. If you cannot do this then add redundant gas orally to the back-up wing and sparingly. However, you should be able to reach both rear dumps simultaneously and vent during ascent. This is no more or less difficult than dumping a drysuit and a wing during ascent.
In a rescue situation, however, the rescuer may find it more difficult to vent gas from two wings. But, this would mean that the diver somehow experienced the need to put gas in the redundant bladder before needing to be rescued. Rescues, though, are rare and messy. My head wasn't totally in the game during my GUE Tech 2 course because my girlfriend of four years broke up with me a day before class. Would you believe I forgot to vent gas from my buddy's drysuit? And, I teach this stuff! What do you think would happen in a rescue in which buddies do not practice rescue skills and now it's real? You'll probably be lucky if most divers keep the airway open. A single wing and drysuit or two bladders would probably cancel one another out as far as complexity under stress if the divers are totally familiar with the way a rig is balanced. "Balanced" doesn't just mean the use of a drysuit and single lift wing.
Dual bladder wings are often shown in the worst images that opponents find useful for propaganda. But, you can find as many terrible pictures of single lift wings with tech configurations. Huge dual lift bungie wings with lots of danglies dwarfing the tanks and their divers are the norm for poorly configured dual bladder pictures. These images are shown the same way hair replacement and weight loss commercials show "before" pictures of clients at their worst angles, frowning or with neutral expressions, and without tans. "After" pictures show clients tanned and smiling from flattering angles. A dual lift wing needs to be properly sized for the cylinders. My Halcyon Evolve 60 dwarfs my AL80's while my Evolve 40 fits the 80's properly. Likewise, without a drysuit, I might wear a Dive Rite 45 pound lift Classic dual bladder wing with steel 85's, 95's or HP100's. The bungie system was removed and I use 12 inch inflator hoses. Since I wear this wet, I use my Halcyon argon bottle strap on the right side of my plate to hold the redundant inflator hose. I can pull the velcro away to free the hose, inflate it, and reach back and stow the hose resealing the velcro.
The rig is streamlined and looks no different than my DIR system at first glance until someone takes a second look and notices the dual lift. It's a standard at PSAI for instructors and students to have either a wing and drysuit or a dual bladder and wetsuit with steel doubles. When my drysuit was FUBAR I started wearing the dual bladder wing and thought I'd hate it. No way! It's really six pros and cons in one hand and half a dozen pros and cons in the other hand as to the suitability of each wing. In flow caves you really are slicker when wet if swimming. A dual bladder in that case has less drag than a drysuit with a larger surface area.
The key is to keep it simple. Remove all entanglements such as bungies from a dual lift wing. Use a lift capacity that is ideal for the tanks you are using. Make sure the inflator hoses are shortened for streamlining in a swimming profile. Secure the redundant hose so that it doesn't hang. NEVER connect the redundant hose to an auto inflator. Practice using the redundant side and dumping gas with your right hand from the rear right dump and corrugated hose. Normally use the BCD from the left side as the working side.
The main advantage of dual bladders is that you would have quality surface lift in the unlikely even of a primary bladder failure. The main disadvantage is that it does add complexity to your rig, but really no more so than a drysuit. A rescue may be more complicated by a right side bladder than just having BCD and drysuit buoyancy on the left.
I prefer to cave dive in steel tanks and drysuit with a single lift wing or wetsuit and my AL80's (no V-weight) with a single lift wing. But, when I do need to dive wetsuit and steels, I like the reduced drag offered by the dual bladder compared to wearing a drysuit. All equipment needs to be well-understood and configured to be used safely.
Last edited: Jan 27, 2013
Edit: I never even considered the implications from a "Rescuer."
Standpoint/Perspective.
Dam......I have a lot to learn.
Cheers.
This is something, I'm highly interested in.
So, as a self proclaimed compressed air junkie...my research begins.
Thanks to all.
Cheers.
Questions about Dual bladder wings
Trace MalinowskiCave Instructor
# of Dives: 5,000 - ∞
Location: Alexandria Bay, NY
Before I learned to use a dual lift wing properly I believed a lot of the rhetoric. There are pros and cons to wearing a dual bladder wing just as there are pros and cons to wearing a drysuit and a single lift wing. The pro of a dual bladder wing is that you have redundant lift in a device that is designed to provide lift. Drysuits are not optimal for redundant lift - especially once the diver reaches the surface and is in a vertical position. Drysuits will often burp gas out of the neck seal. Try an experiment and tread water in heavy steel tanks in open water without the wing inflation. Only use drysuit inflation. What happens? Does your suit burp gas? Do you find yourself struggling a bit? A lot? This will depend upon the diver, what size tanks he is using, and the fit of the neck seal.
I've seen a drysuit fail to suspend a student wearing a DUI TLS-350 when the elbow came off the wing's corrugated inflator hose. The team provided the redundant lift needed by assisting the diver to shore not far away. Had this happened in the ocean awaiting pick-up by boat, the diver whose wing lost gas could have panicked or the team may have decided to ditch the entire scuba rig. Some divers have little problem treading water in high capacity steel tanks without inflation in either the suit or the wing. Others cannot. One's physical prowess and diving skill may also come into play when deciding on a single lift wing vs. a dual lift wing.
Diving environment is also a factor. Are you diving in warm open ocean or in caves? Most caves allow you to push, pull, and crawl your way out of with a buoyancy failure and many will allow you to stand up in shallow water at some point near the exit. In cold open water, you are probably already wearing a drysuit. A drysuit plus a dual bladder wing is needless drag. If you are wearing a drysuit then a drysuit and a single wing is a better bet than a dual lift. Ascent is another issue. If you somehow got gas in the second bladder at depth, you'd now be managing 3 devices in which gas would be expanding during ascent - wing 1, wing 2, and drysuit. Not recommended!
How would gas get in the wing? Well, it shouldn't be from an LP auto-inflator hose. DO NOT ... again, DO NOT connect the redundant inflator/wing to an LP auto-inflation hose! Leave the redundant wing as oral inflate only. Before the dive, fully orally inflate the redundant wing and make sure it is working. Make sure the OPV works just like a single wing. Then dump as much gas as you can and inflate your primary wing all the way with the auto-inflator. Dump the rest of the gas from the redundant wing as you do this. The redundant bladder should now be collapsed.
While it is probably true that most wing tears may come in two's OPV failures and corrugated hose failures will normally only happen to one side or another. I will often remove OPV's in classes and most students never notice. Lost corrugated hoses are a different story. If an OPV fails or if the wing tears near the bottom a diver can drop the trim angle to hold gas in the upper part of a wing maintaining lift. A lost corrugated hose or tear on the top of a wing will be far more difficult to manage.
A couple weeks ago my Halcyon Evolve with 40 lb. lift failed while cave diving at Ginnie thanks to the OPV. I was returning via the Lips Bypass and got stuck. After wiggling free I thought a post or manifold had started to leak because I could hear bubbling above me in the tight space. I flow checked, but couldn't determine the source. It wasn't until I got into bigger passage that I noticed my buoyancy was being lost. As I added gas it was just streaming out the OPV. I monkeyed around with it and then it held. Even with a single wing you can find yourself taking a bit of time to diagnose a wing problem. A dual bladder will complicate diagnosis. For this reason, if you need redundant lift you want to try to avoid adding gas at depth or too much gas. If buoyancy is lost at depth you should attempt to control the ascent with whatever gas you save or add in the primary wing. If you cannot do this then add redundant gas orally to the back-up wing and sparingly. However, you should be able to reach both rear dumps simultaneously and vent during ascent. This is no more or less difficult than dumping a drysuit and a wing during ascent.
In a rescue situation, however, the rescuer may find it more difficult to vent gas from two wings. But, this would mean that the diver somehow experienced the need to put gas in the redundant bladder before needing to be rescued. Rescues, though, are rare and messy. My head wasn't totally in the game during my GUE Tech 2 course because my girlfriend of four years broke up with me a day before class. Would you believe I forgot to vent gas from my buddy's drysuit? And, I teach this stuff! What do you think would happen in a rescue in which buddies do not practice rescue skills and now it's real? You'll probably be lucky if most divers keep the airway open. A single wing and drysuit or two bladders would probably cancel one another out as far as complexity under stress if the divers are totally familiar with the way a rig is balanced. "Balanced" doesn't just mean the use of a drysuit and single lift wing.
Dual bladder wings are often shown in the worst images that opponents find useful for propaganda. But, you can find as many terrible pictures of single lift wings with tech configurations. Huge dual lift bungie wings with lots of danglies dwarfing the tanks and their divers are the norm for poorly configured dual bladder pictures. These images are shown the same way hair replacement and weight loss commercials show "before" pictures of clients at their worst angles, frowning or with neutral expressions, and without tans. "After" pictures show clients tanned and smiling from flattering angles. A dual lift wing needs to be properly sized for the cylinders. My Halcyon Evolve 60 dwarfs my AL80's while my Evolve 40 fits the 80's properly. Likewise, without a drysuit, I might wear a Dive Rite 45 pound lift Classic dual bladder wing with steel 85's, 95's or HP100's. The bungie system was removed and I use 12 inch inflator hoses. Since I wear this wet, I use my Halcyon argon bottle strap on the right side of my plate to hold the redundant inflator hose. I can pull the velcro away to free the hose, inflate it, and reach back and stow the hose resealing the velcro.
The rig is streamlined and looks no different than my DIR system at first glance until someone takes a second look and notices the dual lift. It's a standard at PSAI for instructors and students to have either a wing and drysuit or a dual bladder and wetsuit with steel doubles. When my drysuit was FUBAR I started wearing the dual bladder wing and thought I'd hate it. No way! It's really six pros and cons in one hand and half a dozen pros and cons in the other hand as to the suitability of each wing. In flow caves you really are slicker when wet if swimming. A dual bladder in that case has less drag than a drysuit with a larger surface area.
The key is to keep it simple. Remove all entanglements such as bungies from a dual lift wing. Use a lift capacity that is ideal for the tanks you are using. Make sure the inflator hoses are shortened for streamlining in a swimming profile. Secure the redundant hose so that it doesn't hang. NEVER connect the redundant hose to an auto inflator. Practice using the redundant side and dumping gas with your right hand from the rear right dump and corrugated hose. Normally use the BCD from the left side as the working side.
The main advantage of dual bladders is that you would have quality surface lift in the unlikely even of a primary bladder failure. The main disadvantage is that it does add complexity to your rig, but really no more so than a drysuit. A rescue may be more complicated by a right side bladder than just having BCD and drysuit buoyancy on the left.
I prefer to cave dive in steel tanks and drysuit with a single lift wing or wetsuit and my AL80's (no V-weight) with a single lift wing. But, when I do need to dive wetsuit and steels, I like the reduced drag offered by the dual bladder compared to wearing a drysuit. All equipment needs to be well-understood and configured to be used safely.
Last edited: Jan 27, 2013
Edit: I never even considered the implications from a "Rescuer."
Standpoint/Perspective.
Dam......I have a lot to learn.
Cheers.
