What is the deepest you can do an OOA?

[Adobo]

I'd rather have a HP hose blow than an LP hose but in either case I would just shut down that post. That is something that I practice on every dive. I can do that with no help at all but in all likelyhood my buddy will be right there with long hose ready and to help make sure that I get the right thing shut down and the leak does indeed stop or to provide light, line reference or whatever. IF I was too slow about it or somehow lose too much gas, there's my buddies reserve gas (he/she) is a backup to a backup). If it happened to both of us at the same time (never even heard of that one), we would both be running on one post, sharing gas or even buddy breathing and obviously at less than full strength but we would be alive and on our way home (another three or four failures could do us in for certain, LOL). If we're on a dive where getting to the surface quick isn't practical we each have a bunch more gas than we need for the dive so one or even both of us can actually lose a LOT of gas before it becomes any real threat.

Mike,

To be fair, I think this discussion should start with the assumption that both divers are in singles.

What I have heard with my recreational diving training is that with any issue as serious as a blown hose, the dive is over. If diver 1 blows an LP hose and is losing gas rapidly, he should still have more than ample time to do a gas share with diver 2.

The scenario that was brought up really means, what do they do if diver 2 now experiences a malfunction that leads him to have an OOG emergency as well.

Assuming the worst case scenario with divers that were not being stupid, diver 1 might have experienced the OOG emergency at 130 feet (why he's diving a single to that depth is a whole 'nuther issue). Assume that it takes 1 minute for the donation to occur. Assume that they go straight to the surface (recreational procedures) with the ascent rate of 33'/min. That means there is a window of about 5 mins for diver 2 to all of a sudden experience an equipment failure. And not just any equipment failure, one that leads to a second OOG emergency.

There has to be some analogy that could adequately illustrate how ridiculous this scenario is.

 

[MikeFerrara]

In singles...

I agree an equipent failure like that means the dive is over and you are headed to the surface, exit point or whichever is appropriate for the dive.

If there's any depth to the dive I'd probably still have an h-valve and shut down the same post/valve.

If the dive is shallow and I don't have doubles or an h-valve, even with a free flow or ruptured hose, you should be able to breath off of it long enough to get to the surface.

Then of course there is your buddy and if I don't have one or don't have one I can trust I'm probably not diving.

 

[gangrel441]

It only happens when you are sitting at a desk going "What if........"

Sorry Jeff....seen some pretty improbable things happen with my own eyes....in and out of the diving realm. If you think such occurrences are outside of the realm of possibility, then I can only hope ole' Murph don't decide he has it in for you someday.

Again, we are talking about a low risk, extremely low probability, no equipment solution to a problem that most likely will never occur. You can take all the jabs you want, but I still don't understand what the hang-up is. The best I am getting so far is something like "it's not an option in a cave and it is a bad option on a mandatory deco dive, so I shouldn't consider it ever."

 

[MXGratefulDiver]

Sorry Jeff....seen some pretty improbable things happen with my own eyes....in and out of the diving realm. If you think such occurrences are outside of the realm of possibility, then I can only hope ole' Murph don't decide he has it in for you someday.

Again, we are talking about a low risk, extremely low probability, no equipment solution to a problem that most likely will never occur. You can take all the jabs you want, but I still don't understand what the hang-up is. The best I am getting so far is something like "it's not an option in a cave and it is a bad option on a mandatory deco dive, so I shouldn't consider it ever."

There is no hang-up ... I don't think there's a single person involved in this conversation that wouldn't know how to do a CESA if a nearly-impossible multiple failure required it. You go-and-blow ... and other than the fun that Cerich derives from doing them, what value do you get from practicing it?

Far better to spend your time planning, preparing, and practicing to keep the odds as low as possible. What I don't understand is the emphasis on performing one ... I'd rather put my mindset and energy into figuring out how to resolve my problems without having to resort to an act of desperation ...

... Bob (Grateful Diver)

 

[JeffG]

resort to an act of desperation ...

also an act that requires no real skill. Swim and exhale. I have much better things to do with my time than to practice a CESA, but far be it for me to hinder the Master Diver from practicing it.

 

[gangrel441]

I'd rather have a HP hose blow than an LP hose but in either case I would just shut down that post. That is something that I practice on every dive. I can do that with no help at all but in all likelyhood my buddy will be right there with long hose ready and to help make sure that I get the right thing shut down and the leak does indeed stop or to provide light, line reference or whatever. IF I was too slow about it or somehow lose too much gas, there's my buddies reserve gas (he/she) is a backup to a backup). If it happened to both of us at the same time (never even heard of that one), we would both be running on one post, sharing gas or even buddy breathing and obviously at less than full strength but we would be alive and on our way home (another three or four failures could do us in for certain, LOL). If we're on a dive where getting to the surface quick isn't practical we each have a bunch more gas than we need for the dive so one or even both of us can actually lose a LOT of gas before it becomes any real threat.

Your scenereo had two divers with four posts (two a piece). So in other words, no one should be diving unless they are diving doubles or, at the very least, a Y valve? That'll be a tough sell in the dive industry. If that is where you are coming from, I can't really argue except to say that the dive industry would become a much smaller place, and a lot fewer dollars would go into development of the gear you use. Also, volume sales of gear would plummet, which means everything costs you considerably more.

If your argument comes strictly from a cave or deco standpoint, I can't argue, except that in the case of a deco dive, some extreme and highly improbable (almost beyond imagination) circumstances could leave the surface as the best alternative.

But a buddy pair of rec divers diving singles well within no deco limits and well within the recreational depth limits (read: under 100 ft.) have a very, very slight chance of multiple equipment failures which could lead to the necessity of a CESA. Under the same circumstances, poor gas management (yes, we are human) can also lead one diver to be on the other's alternate, heading for the surface, at the time that the buddy's reg has some form of catastrophic failure.

Do I forsee myself ever having the circumstances that would necessitate me using this procedure? NO! Do I keep it in my back pocket in case things ever really do go brown down there, either through my own screw-up or through hellacious circumstances? WHY NOT? No need to buy any additional equipment, no major investment of time in the training, just an occasional controlled exercises once in a great while? What exactly is at risk here?

If you don't forsee any time that you just might need to use this procedure, and therefore have chosesn to remove it from the tool box, that is your call. God bless, and hope you never need it. For the small investment, I'll keep it around, whether I feel I will ever need it or not. I really have nothing more to say on the subject.

 

[Adobo]

There is no hang-up ... I don't think there's a single person involved in this conversation that wouldn't know how to do a CESA if a nearly-impossible multiple failure required it. You go-and-blow ... and other than the fun that Cerich derives from doing them, what value do you get from practicing it?

Far better to spend your time planning, preparing, and practicing to keep the odds as low as possible. What I don't understand is the emphasis on performing one ... I'd rather put my mindset and energy into figuring out how to resolve my problems without having to resort to an act of desperation ...

... Bob (Grateful Diver)

You're silly Bob.

While only remotely possible, a shark could come and bite you in the arse. I guess we should all be thinking about chain mail suits as well. My scenario is ridiculous also but at least there have been recorded instances of sharks attacking divers. (Nobody ever gets in the water thinking that "whitey will get me today" but you know, it could happen.)

 

[JeffG]

I really have nothing more to say on the subject.

Thank God.

 

[gangrel441]

There is no hang-up ... I don't think there's a single person involved in this conversation that wouldn't know how to do a CESA if a nearly-impossible multiple failure required it. You go-and-blow ... and other than the fun that Cerich derives from doing them, what value do you get from practicing it?

Far better to spend your time planning, preparing, and practicing to keep the odds as low as possible. What I don't understand is the emphasis on performing one ... I'd rather put my mindset and energy into figuring out how to resolve my problems without having to resort to an act of desperation ...

... Bob (Grateful Diver)

There is nothing in your statement above that I disagree with whatsoever, except that for a newer diver, it does provide a level of comfort in the water to practice this exercise. If they know from experience that they can make for the surface if all else fails, they are more likely to keep a calm head as they work through the better alternatives they have learned and trained.

 

[Adobo]

Do I forsee myself ever having the circumstances that would necessitate me using this procedure? NO! Do I keep it in my back pocket in case things ever really do go brown down there, either through my own screw-up or through hellacious circumstances? WHY NOT? No need to buy any additional equipment, no major investment of time in the training, just an occasional controlled exercises once in a great while? What exactly is at risk here?

If you were executing your dive without CESA in your back pocket, how would you dive? That is the risk. Because you have CESA in your back pocket, you might not be incorporating important practices and procedures as part of your diving/dive planning. Every idiot diver in the world (me included) knows that failing all else, head for where there is fresh air. No training required. How many of those idiot divers know the common techniques they can employ to minimize the chance of "failing all else"?

There is nothing in your statement above that I disagree with whatsoever, except that for a newer diver, it does provide a level of comfort in the water to practice this exercise. If they know from experience that they can make for the surface if all else fails, they are more likely to keep a calm head as they work through the better alternatives they have learned and trained.

And by the way, my experience is that new divers have a tendency to go to the surface first after - not an emergency but after any event that causes discomfort. This is one of the bad habits that need to be broken first, is it not?