What is the deepest you can do an OOA?

[gangrel441]

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"?

Again, I don't disagree. CESA is in no way part of my dive plan, unless it is as an exercise. If that is the reason for the disagreement, then either you have misunderstood me or I have misspoken. Again, as I have stated a few times, I have never had to do, nor do I ever plan to have to do a CESA. I bring my kit back with plenty of gas and a buddy in close contact every dive.

We disagree on practicing. This is philosophical. I do a drill two or three times a year. Not a big deal in my book.

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?

<shrug> With 85-ish dives under my belt, I have never felt the urge to bolt for the surface. My wife, with 60-ish dives under her belt, hasn't felt that urge since her second checkout dive. We've had an occasional issue that has come up. We have dealt with it and continued the dive, or we have thumbed the dive. I never felt that CESA exercises instilled in the divers that bolting to the surface is a solution to all problems. If you feel it has, I can understand the rest of where you are coming from. It hasn't been my expeience.

 

[Bill51]

This thread has caused me to do some thinking about what I subconsciously do on many dives (and hadn&#8217;t paid much attention to until now). My apparent comfort zone for an OOA CESA varies from 60-90&#8217; depending on the conditions and my buddy, based on realizing that at a certain depth I find myself maintaining a closer proximity to my dive buddy. Under most conditions with most buddies I do have a tendency to be a same ocean buddy down to about 60&#8217; and more so if I&#8217;m shooting video and my buddy is bored watching me, but once I start getting deeper I will start closing the gap between us.

 

[spectrum]

you're by yourself with a single tank that won't give you air.

1. How many divers going around testing the limits of this. Especially at the risk of , as you say "getting sick". ?

2. Even if somebody said they did it OK from 120 feet many factrors entered into this such as what their last breath was like and their starting buoyancy etc, etc.

3. If you plan to be deep enough to worry and alone then you need a redundant air supply or you own angel.

The most I care to do is practice it ocassionally from a safe depth so I am comfortable with the concept. The rest of my energy is better directed to avoidance.

No I didn't read the 300 prior posts

 

[Dan Gibson]

OK, don't be alarmed. That was just probably a poor description. I should have said less risky or not as risky. The only way to totally eliminate risk is don't even drive to the dive site since that is typically more dangerous than diving.

Your example is a stretch. As others have pointed out, the blown LP hose is far worse. Hoses typically show signs that they may be about to go. Always check your gear before dives. A quick bubble check under water with your budddy or team will also likely reveal some minor bubbles indicating something is up. With single 80s, a shallow dive is easy to manage the ascent. With depths like 130 ft, one can always say why do the dive on a single 80. Since we need to reserve enough gas for ourselves and our buddy in case of an emergency, the volume available to do the dive usually isn't enough to do any significant bottom time. I know a lot of people won't be happy with being told it's not the best idea to dive single 80s to 130 ft. It's just another example of how some of us choose to mitigate the risks.

Give some more examples. I'm sure these examples can be shown to not be instant CFs.

Dan - One comment in your last post alarms me...



Risk mitigation or risk management limits or controls risk, but never completely eliminates it. The only way to eliminate risk is to achieve perfection. Have you accomplished this yet? Last I checked, no one has.

As for the rest...the scenereo I can see off the top is here...I have witnessed multiple hose blowouts among a few very capable and well-prepared divers. It is a stretch, but I could concieve of a pair of very experienced divers who, through the sheer will of Murphy, managed to blow the HP hoses on both of their rigs at the same dive. Unlikely? Very. Preventable? Perhaps if there was visible wear on the HP hoses or the regs hadn't been maintained, but what if both regs were serviced in the same place, both HP hoses had been replaced, and the hoses had a material defect?

 

[fweber]

Jeez! I can't believe this thread is still going on. So, can everybody agree with?

A CESA is the last ditch option where you no longer have breathable gas, a redundant source, nor available buddy. As such you should do everything in your power to prevent ever having to perform one. This includes but is not limited to proper equipment maintenance, pre-dive planning including gas planning, and buddymanship. However, it has been shown by accident alalysis that frequently it's not a single failure that results in a casualty but a series of events which not unussually results in panic and the unfortunate outcome. So, in an effort to prevent such panic from ensuing and thereby distracting the diver from pursuing other more appropriate options, all dives should be require to perform a CESA during their basic training, from some depth that requires them to exhale while ascending. That all divers should realize they can perform this maneuver from any recreational depth. And that they should practice this manuever until they can do so with some proficiency, this may take but once for some or more for others.

Am I missing something or is this more or less what everybody agrees upon?

The OP just wanted to know from what depth a CESA can be performed. The answer seems to be agreed upon as: Deeper than the limits of the recreatinal NDL tables.

 

[Dan Gibson]

It's never going to happen since Nemrod will always be odd man out

Jeez! I can't believe this thread is still going on. So, can everybody agree with?

 

[gangrel441]

Jeez! I can't believe this thread is still going on. So, can everybody agree with?

A CESA is the last ditch option where you no longer have breathable gas, a redundant source, nor available buddy. As such you should do everything in your power to prevent ever having to perform one. This includes but is not limited to proper equipment maintenance, pre-dive planning including gas planning, and buddymanship. However, it has been shown by accident alalysis that frequently it's not a single failure that results in a casualty but a series of events which not unussually results in panic and the unfortunate outcome. So, in an effort to prevent such panic from ensuing and thereby distracting the diver from pursuing other more appropriate options, all dives should be require to perform a CESA during their basic training, from some depth that requires them to exhale while ascending. That all divers should realize they can perform this maneuver from any recreational depth. And that they should practice this manuever until they can do so with some proficiency, this may take but once for some or more for others.

Am I missing something or is this more or less what everybody agrees upon?

The OP just wanted to know from what depth a CESA can be performed. The answer seems to be agreed upon as: Deeper than the limits of the recreatinal NDL tables.

100% agreed, and if anything I have said diverges from this, then I must have misspoken.

My emphasis on the occasional drill is mainly to keep the idea fresh.

 

[gangrel441]

I guess a big part of my point is that, even if something could have been caught through preparation and safety checks, that doesn't necessarily mean it will be caught. We are, after all, human. I think we can all agree that there is an occasional, unforseeable malfunction of gear. I would also hope we all agree that as humans, we all do have the occasional brain fart, regardless of how well we think we have prepared ourselves. The worst case scenereo I keep coming back to is the brain fart leading to a failure of the primary, followed by an equipment malfunction on the backup.

Again, if you have done this procedure enough to be comfortable with it (and perhaps, as one poster stated earlier, that is once), then you would see no need to drill it. My concern is that a newer or less frequent diver may think surface and, (as one poster said in his own words earlier) hold his breath while swimming to the surface. Now we have LOE and a possible AGE on our hands. Had said diver known (not from book knowledge, but from training and practice) that you don't need to hold your breath on a CESA to have air in your lungs all the way up, this scenereo would play out better. I know blow and go, you know blow and go, but it is not intuitive for everyone.

OK, don't be alarmed. That was just probably a poor description. I should have said less risky or not as risky. The only way to totally eliminate risk is don't even drive to the dive site since that is typically more dangerous than diving.

Your example is a stretch. As others have pointed out, the blown LP hose is far worse. Hoses typically show signs that they may be about to go. Always check your gear before dives. A quick bubble check under water with your budddy or team will also likely reveal some minor bubbles indicating something is up. With single 80s, a shallow dive is easy to manage the ascent. With depths like 130 ft, one can always say why do the dive on a single 80. Since we need to reserve enough gas for ourselves and our buddy in case of an emergency, the volume available to do the dive usually isn't enough to do any significant bottom time. I know a lot of people won't be happy with being told it's not the best idea to dive single 80s to 130 ft. It's just another example of how some of us choose to mitigate the risks.

Give some more examples. I'm sure these examples can be shown to not be instant CFs.

 

[Rick Murchison]

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

Also happens when two young bucks are on their first excursion to 80' and not paying attention to their gas... I "happend by" such a pair, busily looking in nooks and crannies. I knew they were newbies, and felt like they'd been down a bit long for their experience and gas supply, so I went over to check. 200 and 300 psi respectively... I handed my primary to the 200 psi guy while hauling them up into a normal ascent - they also had 6 minutes deco on their computers! Stopped 'em at 10' and as the 300 psi guy's gauge read 0 had the 200 psi guy take his own reg back and handed my primary to the now OOA 300 psi guy - got about a four minute stop in before they had to surface.
'Twould have been interesting had I not been there...
My point: terminal stupidity can generate any scenario you care to imagine
Rick

 

[Adobo]

Again, I don't disagree. CESA is in no way part of my dive plan, unless it is as an exercise. If that is the reason for the disagreement, then either you have misunderstood me or I have misspoken. Again, as I have stated a few times, I have never had to do, nor do I ever plan to have to do a CESA. I bring my kit back with plenty of gas and a buddy in close contact every dive.

We disagree on practicing. This is philosophical. I do a drill two or three times a year. Not a big deal in my book.

I guess you're right. Keeping CESA in your back pocket is important. Much like jumping out of your moving car should be an option in your back pocket. You never know what you never know.