padi ow, why is CESA recommended to 9m?

[boulderjohn]

If the OP is indeed taking a class, and found that in his manual, then his manual is not current and the class is not being taught to standards.

But if he is reading an old manual, c1994 (version 1), then on page 155 it says to drop weights and/or inflating your BCD. The next version of the manual I have in my library is 1999 (version 2.1) and it just says (p159) to drop your weights. And the latest version, 2013 (Version 3) agrees, ditch your weights (p161) to get buoyant. Note that the old option of "buddy breath with a single regulator" no longer exists in Version 3. So now there are only four ways taught to get to the surface: normal, your buddy's alternate air source, CESA, and emergency buoyant ascent.

I can't find the thread, but there was one on this topic maybe 4-5 years ago. I sent an email to PADI HQ for an explanation, and they referred to new (then) wording that was more ambiguous about the depth. When I give the exams now, though, I don't see that ambiguity. I really think they want you dropping your weights past that depth. They want to make sure you get to the surface. Yes, you should be able to do a CESA from 100 feet or more, but if you drop your weights and flare, your ascent should not be ridiculously fast, and the CESA skill of exhaling the whole way is still in effect.

As for the wording of inflating the BCD when you are out of air, remember that this section of the course is for low on air and out of air emergencies. The first option is the normal ascent, breathing all the way. in that situation, the BCD could be inflated, although that is not the ideal choice and probably the reason it isn't mentioned any more.

 

[beanojones]

Personally I don't like the idea of teaching CESA. You should never get yourself in that situation. You could do a CESA from 18m (I know an idiot who has done it from much deeper) but it is not something I would practice as a) it isn't worth the risk and b) I don't plan on ever being in that situation c) I know a number of instructors who have ended up in the pot from teaching it.
.

(I wonder if I am that idiot? I have certainly practiced them from arbitrarily deep depths, and recommend them to anyone thinking about doing solo dives or deep dives, and anyone who is thinking about working as a guide in the real world.)

Because I really do think that being able to do CESAs from arbitrarily deep depths should be thought of as a basic skill to dive to that depth and I think that PADI even mentioning buoyant emergency ascents is a really, really bad idea.

Fact is, CESA from arbitrary depths was a basic skill in the old days because it was just a fact of life, with no gauge and no octo. Even in modern times, dive enough or dive for a living, and it will still happen. As a working guide, it's my job to be capable to handle just about anything without getting into a slap fight with a panicked OOA diver.

Why not be able to do it from 18m, or even 100 feet if one feels comfortable diving to 100'? Why not think of the maximum depth from which one is able to comfortably do a CESA as the personal maximum depth for diving? Really, until you put that one's personal max depth as the depth from which one can comfortably do a CESA, personal depth limits are beyond arbitrary. (Says the guide who routinely catches just certified OW divers trying to hit 30m because they have no reason not to go there other than "someone said not to. If a diver thinks that they have to be able to ascend via CESA comfortably from whatever depth they are at, they will most definitely think twice about breaking recommended depth limits, because there is a particular 'required' skill they themselves understand they lack.)

 

[Goodtime Adventures]

I do agree with many posters that if you are taught the fundamentals properly, and continue to be a prudent diver who exercises good judgement, buddy team efficiency etc, that emergency ascents should be a completely unnecessary evil. But they do still need to be taught. The underwater world is not one that naturally sustains life without air, so to not give students a thorough explanation of 'worst case scenarios' and what do do if things go wrong, along with teaching them the contingency skills to deal with such situations would be doing them a disservice IMO. The nitty gritty of how these situations are explained, taught and practiced across the different agencies is a matter of contention and discussion that could go on forever among the instructor and diver community - enough to keep another thread going for a good while I reckon! - but when it comes down to it, the standards are the standards, so while we can add value to our lessons by adding additional information, our opinions and experiences, we still have to teach it.

So...in terms of the original question regarding the 9metre standard, I'd say it comes down to safety in terms of the agency making a judgement call on how long divers are generally going to be able to continuously exhale for. With PADi the max asc rate is 18m per min, so if you are right on the limit 9m should take 30 seconds. Now remember this is the limit, not a target. Slower is always better! Most people can continuously exhale for about 20-30seconds (ie from 6-9m) whilst making the recommended 'aaaaah' sound. Yes, I know lots of divers practice this and could (should?) be able to do it for much longer, but at entry level this is pretty much the norm. For PADI to recommend the CESA from any deeper would most likely have the effect of a) divers ascending too quickly to achieve the ascent on a single breath, b) exhaling too quickly resulting in a breath hold towards the end of the ascent, or c) both of these.

Please bear in mind that this is just my personal thoughts on the matter - I have no idea whether this is actually the logic PADI used to come up with the standard, but it makes sense to me.

Also an additional note to the OP based on this and other questions that you have been posted....as many other poster have said, all the information you're seeking should be covered in your course, so don't get too hung up on all the 'what ifs' and technicalities for now - you haven't even been in the water yet! Just relax and enjoy it - and make sure you discuss all of your questions again with your instructor as you progress throughout your course.

Happy diving and welcome to the addiction, I hope you enjoy your OW

 

[boulderjohn]

So...in terms of the original question regarding the 9metre standard, I'd say it comes down to safety in terms of the agency making a judgement call on how long divers are generally going to be able to continuously exhale for. With PADi the max asc rate is 18m per min, so if you are right on the limit 9m should take 30 seconds. Now remember this is the limit, not a target. Slower is always better! Most people can continuously exhale for about 20-30seconds (ie from 6-9m) whilst making the recommended 'aaaaah' sound. Yes, I know lots of divers practice this and could (should?) be able to do it for much longer, but at entry level this is pretty much the norm. For PADI to recommend the CESA from any deeper would most likely have the effect of a) divers ascending too quickly to achieve the ascent on a single breath, b) exhaling too quickly resulting in a breath hold towards the end of the ascent, or c) both of these.

Please bear in mind that this is just my personal thoughts on the matter - I have no idea whether this is actually the logic PADI used to come up with the standard, but it makes sense to me.

First of all, remember that you must exhale all the way from whatever depth you are diving.

Next, being able to exhale for a length of time is quite different if you are ascending. Expanding air will multiply your ability to exhale. You can exhale all the way from 100 feet in a controlled ascent because of that.

Finally, remember that your cylinder is not actually out of air. It just does not have enough air to be able to deliver it through the regulator at that depth. As you get shallower, you will be able to inhale.

 

[Max Speed]

If I had not been taught how to properly do a CESA I would have died on my 3rd open water checkout dive. Several standards violations by the instructor led to that dive being a night dive to 75 feet. My borrowed Russian regulator froze shut. ( one of the few designs which would )

I had just exhaled. No inhale, no bc inflate. Buddy goes bug eyed at out of air signal and backs away. I couldn't even see an octo on him because he had an Air 2 which I didn't even know existed.

Made the swim up but dropped weight belt on the way. Barely made that ascent. Blowing bubbles the whole way is the easy part.

Fortunately we had thoroughly trained on avoiding bursting ones lungs.

Decided that relying on buddy is stupid. Bought a spare air and then a pony bottle.

That dive was also conducted with a single light which had to be hit occasionally when it would auto off...

 

[String]

the book says if ooa, & your buddy is far, if you are less than 9m deep do cesa (controlled emergency swimming ascent) , but if you are deeper inflate your bcd to do an uncontrolled bouyant ascent

the latter sounds like a death sentence. why couldnt cesa be the method of choice for 18m depth? since you have some remnants of compressed air in your lungs you should (i guess) be able to swim that long minute to the surface?

anyone practise cesa in their training from these depths?

thx

It could be used much deeper than 18m *provided you get it right*. The "Bolt 'n' Pray" is an outdated dinosaur of a skill that some progressive agencies don't teach and really has no place in modern diving. It's a legacy from the non AAS, non buddy breathing days.

To get to the stage where you need a CESA you've already done several things wrong and ignored your training on a few issues. Firstly, you've lost your buddy. Then you didn't abort the dive. Then you've managed to run out of gas as well. Given the person is incapable of doing those first 3 easier things theres nothing to suggest they'll get the far more complicated and dangerous CESA correct especially when absolutely paniced as they're out of gas. And that's from 9m. Imagine them doing a bolt and pray from 18m or deeper in those situations! A real life CESA *WILL* be a rapid ascent. Guaranteed

As above, i know a few people who have ended up in the pot from teaching it. It's not a safe skill for the students or the instructor in general and as i've said above, don't believe its needed at all OR solves any problem. I teach all mine from 6.0m. Never deeper - i can't justify it on a risk assessment. An ex-manager of mine said he'd fire anyone teaching it from less than 6m and deeper than 6.1m and i agree with his view entirely.

I really can't see why someone would want to practice a skill that comes into play once they've completely screwed up many other much simpler aspects of their dive.

Also, what's all this talk about inflating the BCD when out of air? Surely you're out of air so what are you going to inflate it with?

 

[Mustard Dave]

(I wonder if I am that idiot? I have certainly practiced them from arbitrarily deep depths, and recommend them to anyone thinking about doing solo dives or deep dives, and anyone who is thinking about working as a guide in the real world.)

Because I really do think that being able to do CESAs from arbitrarily deep depths should be thought of as a basic skill to dive to that depth and I think that PADI even mentioning buoyant emergency ascents is a really, really bad idea.

The idiot in question was bloke who joined our club. He is in his fifties and said he's been diving over 25 years. His paperwork supported everything he said. When I met him, I could tell he was a bit of a knob. He was an old school BSAC diver and if you didn't do something his way, you were wrong.

Some lads from the club dived with him at Capernwray, our local inland dive site. At the entry point, there is a steep drop to around 17m, where there is a turboprop plane with the cabin door removed and the tail section cut off. They jumped off the jetty and he dropped like stone. On the bottom he was crawling, kicking up the silt as he went. He got to the cabin door and the others were chasing him to stop him going inside. He climbed into the plane, crawled through it and fell out at the back. They grabbed him and dragged him up the slope and got him out of the water.

When they were on the surface he bollocked them and said he didn't need any help. He told them if he'd had a problem, he would have ditched his kit and swam up, and he's done it from 40m before.

I was on a trip with him shortly after. I did everything I could to make sure I didn't have to share a car, a room or dive with the pillock. I lost count of the number of times he told us about the number of times he'd dumped his kit and swam to the surface. Fortunately he has never been back since then.

Fact is, CESA from arbitrary depths was a basic skill in the old days because it was just a fact of life, with no gauge and no octo. Even in modern times, dive enough or dive for a living, and it will still happen. As a working guide, it's my job to be capable to handle just about anything without getting into a slap fight with a panicked OOA diver.

Why not be able to do it from 18m, or even 100 feet if one feels comfortable diving to 100'? Why not think of the maximum depth from which one is able to comfortably do a CESA as the personal maximum depth for diving? Really, until you put that one's personal max depth as the depth from which one can comfortably do a CESA, personal depth limits are beyond arbitrary. (Says the guide who routinely catches just certified OW divers trying to hit 30m because they have no reason not to go there other than "someone said not to. If a diver thinks that they have to be able to ascend via CESA comfortably from whatever depth they are at, they will most definitely think twice about breaking recommended depth limits, because there is a particular 'required' skill they themselves understand they lack.)

What if you have an overhead (either a wreck/cave or a decompression obligation)? I appreciate this is the basic scuba discussion forum, and 'recreational' divers shouldn't be in that situation, but technical divers have developed skills and equipment configurations that ensure they always have an alternate gas source. I do not see a reason why recreational divers shouldn't have a redundant gas source, be it on their person or their buddy. It is incredibly important to tell students to always exhale on an OOG ascent, but I do not see the need to practice it. If you are ever in the situation you need to do a CESA, you have really made a bollocks of things big time!

If I had not been taught how to properly do a CESA I would have died on my 3rd open water checkout dive. Several standards violations by the instructor led to that dive being a night dive to 75 feet. My borrowed Russian regulator froze shut. ( one of the few designs which would )

I had just exhaled. No inhale, no bc inflate. Buddy goes bug eyed at out of air signal and backs away. I couldn't even see an octo on him because he had an Air 2 which I didn't even know existed.

Made the swim up but dropped weight belt on the way. Barely made that ascent. Blowing bubbles the whole way is the easy part.

Fortunately we had thoroughly trained on avoiding bursting ones lungs.

Decided that relying on buddy is stupid. Bought a spare air and then a pony bottle.

That dive was also conducted with a single light which had to be hit occasionally when it would auto off...

There are two ways to look at that. One is being able to do a CESA saved your arse - the other is a piss-poor instructor put you in a situation that could have killed you.

 

[String]

the other is a piss-poor instructor put you in a situation that could have killed you.

That really. If the instructor can't teach the basic skills then how do they think he can teach a CESA ?

 

[NAM001]

I have the 2013 manual in fromt of me. Page 161 When running out of air or LOW on air. Order of usage
1. Make normal Ascent
2. Ascend using alternater air source
3. CESA (6-9M)
4. Make buoyant emergency ascent (same as cesa only after droping weights)

 

[String]

2014 is the same. The "new" OW course has introduced a surface weight drop skill too