If you are diving balanced then at the end of the dive you should have minimum gas weight so should be easier to swim up / hold stops
Your thoughts on dual bladder wing
- Thread starter CAPTAIN SINBAD
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The Chairman
Chairman of the Board
It's not hard to understand: They don't do those kinds of dives. When others say I can't dive in a particular way, I often say 'watch me' under my breath as I splash to do that very dive.
Ayisha
Contributor
A balanced rig from page 107 of GUE's "Doing it Right: The Fundamentals of Better Diving":
"The ideal configuration for a diver is one that, while being as light as possible, allows him/her to remain neutral at 10’ (3m) with a nearly empty set of tanks (to allow for decompression/safety stops).... Divers should be certain that, without any air in their buoyancy compensators, they are capable of swimming against the weight of their configuration with full tanks and all weight in place. This would allow them to verify that they are able to manage their SCUBA configuration in the event of a buoyancy failure".
In other words, at the *start* of the dive, to be able to surface from depth/the deepest point with a full tank and a wing failure. At the *end* of the dive, to hold a 10 foot stop and make a controlled ascent with an almost empty tank.
I think the part about "With air drained from drysuit" is a typo, or a misunderstanding of the concept.
See PfcAJ's and Ayisha's posts above. A "balanced rig," as I've always understood it, doesn't mean swimming huge, full, really heavy steel cylinders up at the beginning of a dive if a wing fails, which is difficult if not impossible. It means either (a) having a drysuit to provide redundant buoyancy, or (b) not needing a drysuit or anything else for redundant buoyancy, because you're diving aluminum bottles. Right?
PfcAJ
Contributor
I recognize that with heavy steels you legit might not be able to swim them up even if you have a drysuit. However, wearing a drysuit provides an immediate way to establish positive buoyancy: push the inflate button.
All the other "solutions" do not. They require fiddling with something.
Ayisha
Contributor
That is not my understanding of my post. I dive a 7 mm 2 piece wetsuit with a HP steel 80 tank with 4 lbs of weight in fresh water. I would not have passed the Fundamentals course if my configuration was not balanced. I can swim up my rig with an empty wing and maintain a 10 foot stop and controlled ascent. I use a steel tank because it's shorter and actually fits my body. If you're talking about larger steel tanks or double steel tanks, then you're correct, it would not be a balanced rig with a wetsuit. Aluminum tanks are recommended most of the time, but if you can show that you are balanced, maintain correct trim, etc., then each case is evaluated on its own.
The test that CptTightPants21 mentioned is a very common test to check that you are actually diving a balanced rig. The first time I tried a HP steel 80, I swam up as soon as I descended no problem from depth with an empty wing. For the 10 foot check at the end of a dive, I already know that my wing is empty/nearly empty and that I am easily maintaining the stop and correctly weighted. If you're not sure, you can just reach back and feel the wing. If you have air in the wing at the safety stop and you have to empty the wing, you already know you are overweighted. Best not to actually empty it at the safety stop and think about taking off 2 pounds and see how that goes on the next dive.
Appreciate what you are saying and understand what you have achieved with balanced rigs. However this then suggests that it would be impossible to dive deep with a balanced rig. To do an 80m dive with twin 15 or 18 litre in a wetsuit and to be able to swim up without dropping weight would be difficult if not impossible. Add to that sling tanks (which we agree are accessories and can be dropped) and it becomes even more so impossible.
So my thoughts are that you can create a balanced rig for some styles of diving but not all. At the extremes where divers are going to 300 m with 4 x 18 litre tanks (back gas) there is no way you can balance a rig. At the other end of the scale, I easily have a balanced rig when diving single tank and BCD down to say 40 m, recreational diving. At some point in between recreational diving and deep technical diving balanced rigs become only theoretical and not practical.
Those are my thoughts anyway.
DevonDiver
N/A
Highlighted the issue obstructing your line of reasoning.
But even in a dry suit, isnt balance rig, no gas in drysuit, no gas in wing with backgas and weights swim to the surface? To say you can use a dry suit, then suggests its not a balanced rig, as you are now using additional buoyancy?
Or are we suggesting that using a dry suit as additional buoyancy is ok and thus balanced?
DevonDiver
N/A
That's my take on it. However, the issue isnt just about having a redundant buoyancy source... it's the fact that a drysuit doesn't compress and loss buoyancy as you descend.
In a wetsuit, using ali cylinders, you'd have ditchable ballast in the form of lead weights. But, IMHO, there's also a reasonable point where you stop wearing thicker neoprene and invest in a drysuit.
The important factor, as it was explained to me years ago, was that ditchable ballast (lead or eqpt) plays a critical role in allowing the diver to make a swimming ascent during the early phase of the dive when they're still comparatively negative from the weight of gas.
In the later phase of the dive, gas consumption increasingly alleviates the need to jettison ballast. As they increasingly approach neutral buoyancy not only is a swimming ascent easy, but also holding stops becomes feasible.
Balanced rig comprises both the balance of exposure protection and cylinder selection... and the balance of ditchable versus non-ditchable ballast.
I think it represents a deft solution to the issue of buoyancy loss... but simultaneously requires a very diligent, uncompromising and informed approach. Every aspect of your kit and its characteristics needs to be scrutinized in a holistic and disciplined manner. And, of course, it must be diligently and rigorously tested before it should be relied upon.
In contrast, dual-bladder BCDs offer more flexibility for equipment changes and varied dive parameters. That's useful for many tech divers. They also eliminate the potential for having to jettison expensive kit in a buoyancy emergency.
Lastly, approaches like 'use a lift bag' tend to benefit tech divers who can't be bothered to really mitigate the risk of buouyancy loss... and prefer the ultimate convenience of a risk mitigation solution that relies on a formidable stress management ability, elite-level skills and the assurance that failing to apply a very timely and successful response will kill them. Or, of course, the solution is just rooted in an unshakeable belief that the issue just won't ever really happen to them... or if it does, that it'll be under the same benign and undemanding training conditions as the sole time they ever tried doing it.
In a wetsuit, using ali cylinders, you'd have ditchable ballast in the form of lead weights. But, IMHO, there's also a reasonable point where you stop wearing thicker neoprene and invest in a drysuit.
The important factor, as it was explained to me years ago, was that ditchable ballast (lead or eqpt) plays a critical role in allowing the diver to make a swimming ascent during the early phase of the dive when they're still comparatively negative from the weight of gas.
In the later phase of the dive, gas consumption increasingly alleviates the need to jettison ballast. As they increasingly approach neutral buoyancy not only is a swimming ascent easy, but also holding stops becomes feasible.
Balanced rig comprises both the balance of exposure protection and cylinder selection... and the balance of ditchable versus non-ditchable ballast.
I think it represents a deft solution to the issue of buoyancy loss... but simultaneously requires a very diligent, uncompromising and informed approach. Every aspect of your kit and its characteristics needs to be scrutinized in a holistic and disciplined manner. And, of course, it must be diligently and rigorously tested before it should be relied upon.
In contrast, dual-bladder BCDs offer more flexibility for equipment changes and varied dive parameters. That's useful for many tech divers. They also eliminate the potential for having to jettison expensive kit in a buoyancy emergency.
Lastly, approaches like 'use a lift bag' tend to benefit tech divers who can't be bothered to really mitigate the risk of buouyancy loss... and prefer the ultimate convenience of a risk mitigation solution that relies on a formidable stress management ability, elite-level skills and the assurance that failing to apply a very timely and successful response will kill them. Or, of course, the solution is just rooted in an unshakeable belief that the issue just won't ever really happen to them... or if it does, that it'll be under the same benign and undemanding training conditions as the sole time they ever tried doing it.
