Why not go to 100' ?

[CuzzA]

Some advice I received from another diver regarding CESA....

Find yourself a flight of stairs, would be a good idea to have a spotter follow you, exhale normally and stop just before you would take your next breath and start walking up the stairs. See how far you can go before you simply can no longer fight the urge to breathe.

 

[Freewillow]

Too fast ascents ARE DANGEROUS.

In a lot of countries, most dive docters have asked to take away from the standards of training the CESA from large depth. The reason was that a lot of Accidents - some of them leading to deaths - have been observed because of the training of this technique. Proper dive techniques make CESA an obsolete and dangerous solution.

 

[DevonDiver]

Find yourself a flight of stairs, would be a good to have a spotter follow you, exhale normally and stop just before you would take your next breath and start walking up the stairs. See how far you can go before you simply can no longer fight the urge to breathe.

Nice concept...and good to apply it to CESA

I have some slides which I show my Deep Diver students which put depth into perspective. Most divers don't appreciate the depths they dive to.

So, for a 100ft/30m CESA you are talking about a 7 story building. Anyone confident to walk up 7 stories with empty lungs?

and here's what 130ft/40m looks like:

 

[CuzzA]

Nice concept...and good to apply it to CESA

I have some slides which I show my Deep Diver students which put depth into perspective. Most divers don't appreciate the depths they dive to.

So, for a 100ft/30m CESA you are talking about a 7 story building. Anyone confident to walk up 7 stories with empty lungs?

and here's what 130ft/40m looks like:

I thought so, gotta credit dumpsterDiver with that one.

YES! Those pictures put it into perspective just how deep 70' or 130' is. We would get a little bit of benefit from expanding gas and less gravity, but still, it's a looong ways to the surface with empty lungs.

 

[Dan]

Good info & self check. Thanks!

 

[DevonDiver]

Too fast ascents ARE DANGEROUS.

Obviously.

But as CESA is a CONTROLLED Emergency Swimming Ascent. That means you don't ascend fast. You should have learned that en-route to getting your DM qualification.

In a lot of countries, most dive docters have asked to take away from the standards of training the CESA from large depth.

You kinda just made this up, didn't you?

The reason was that a lot of Accidents - some of them leading to deaths - have been observed because of the training of this technique.

Something else you just made up.

Read this: A Training Agency Perspective on Emergency Ascent Training

Read this: DAN - Theory Into Practice-Emergency Ascents: Managing the Risks

"In a recent analysis of 964 diving fatalities, we found that emergency ascents were involved in 30 percent of cases [...] In 10 percent of emergency ascents, divers attempted a free ascent without using a breathing gas supply.[..]

The most common cause of death in fatal emergency ascents is arterial gas embolism (AGE), accounting for 54 percent of cases, followed by drowning at 18 percent, acute cardiac events at 7 percent and decompression sickness at 5 percent.[...]

Emergency ascents are a response to a life-threatening situation underwater. Despite the urgency in the circumstances surrounding them, with proper training, practice and preparation, they can and should be the safe solution they are intended to be."​

Read this: South Pacific Underwater Medicine Society (SPUMS) - Workshop on Emergency Ascent Training

Read this:

SPUMS POLICY ON EMERGENCY ASCENT TRAINING [LINK]

The SPUMS policy on EAT developed at the 1993 Workshop is summarised below.

1 The frequency of recreational divers becoming low on air or running out of air completely is unacceptably high. Instructor agencies must increase the training emphasis on attention to air supplies and to avoiding unnecessary inflation of buoyancy vests, especially when air supplies are low. The latter will also require an improvement in buoyancy control. The availability of alternative air supplies does not obviate the need for avoiding low on air and out-of-air situations. A sonic reserve alarm may be helpful.

2 An alternative (i.e. independent; e.g. SPARE AIR or redundant scuba cylinder) supply of air is recommended for deep diving (beyond 30 m), cave diving, penetration wreck diving, staged decompression diving and other diving where entanglement is likely. The alternative supply must be appropriate to the circumstance.

3 Emergency ascent training should be taught to and practised by entry level scuba trainees.

a Academic information only Positive buoyant ascent (when the diver drops his or her weights and utilises lift from all forms of buoyancy, BCD and exposure suit).1

b Academic information and confined water (eg pool or lagoon) skills training Weight-belt removal and buddy breathing, when two or more divers share a common air supply by passing the regulator second stage from one diver to another.1

c Academic information, confined and open water skills training.

Emergency (controlled) swimming ascent (when the diver swims to the surface with the regulator in the mouth, exhaling continuously), octopus assisted ascents (using an alternative air source, usually an additional second stage known as an octopus regulator) and normal ascents (a direct swimming ascent, with the mouth-piece in place).

4 Emergency ascent training to the surface should be confined to a maximum depth of9 m.

5 Emergency ascent training should be conducted vertically and involve a vertical safety-line.

6 The number of students per instructor, the number of assistant instructors and the conduct of EAT should be organised to minimise the number of ascents that instructors and their assistants have to perform.

7 The safety and efficacy of buddy breathing is suspect and is under active review.​

Some other background reading:

• Samson RL, Miller JW (eds.) (1979). "Emergency Ascent Training.". 15th Undersea and Hyperbaric Medical Society Workshop. UHMS Publication Number 32WS(EAT)10-31-79.
• Walker, D (1978). "Emergency Ascents: some background information.". South Pacific Underwater Medicine Society Journal. 8 (2). ISSN 0813-1988. OCLC 16986801.
• Knight, J (1978). "Free Ascent Training.". South Pacific Underwater Medicine Society Journal. 8 (2). ISSN 0813-1988. OCLC 16986801.
• Egstrom, GH (1978). "Ascents.". South Pacific Underwater Medicine Society Journal. 8 (2). ISSN 0813-1988.OCLC 16986801.
• Curtis, ASG (1978). "Free Ascents: A view from the Scottish Sub-Aqua Club.". South Pacific Underwater Medicine Society Journal. 8 (2). ISSN 0813-1988. OCLC 16986801.
• Graver, DK (1978). "In support of emergency ascent training.". South Pacific Underwater Medicine Society Journal. 8(3). ISSN 0813-1988. OCLC 16986801.

Proper dive techniques make CESA an obsolete and dangerous solution.

That's your opinion, which you have a right to share. It's important for readers to note that this opinion is not shared by DAN, SPUMS nor any training agency.

CESA is a last resort to an OOA situation. If performed correctly, from an achievable depth, it represents a safe solution for the diver.

In recent years, PADI has made more emphasis on the depth range at which a CESA can reasonably be performed. This has led to some changes that suggest a BUOYANT emergency ascent might be a preferable option at deeper depths.

Obviously, carrying redundant/emergency gas is the best way to avoid an OOA emergency in the first place. Prevention is better than cure.However, scuba divers still do need a formally trained resolution for being OOA.

Prevention first... cure second. You can't say that the cure is obsolete.

Suggesting that emergency ascent training is obsolete is dangerous aand foolhardy. Every diver needs that capability to ascend safely without a gas supply... as a last resort. If nothing else, it's critical training to avoid AGE through lung-overexpansion injury (one of the biggest killers in OOA emergencies).

 

[DiverDawg1]

Diving deep is easy and fun- until it isn't. Have you ever dealt with a burst o ring while in the water? I did, on my fifth dive after certification, right after buying my brand new regulators. I was in about fifteen feet of water and it was a bummer because it ended a day of diving.

On dive fifteen, my log book reminds me that I lost a fin in about 35' of water. New spring straps on new boots. Turns out your fins and boots have to fit each other. You change your boots, you have to make sure your spring straps fit the same as they fit on the old boots. Who knew? It's not in the manual... Hey, did your open water class teach you that you can efficiently swim with one fin? You can. Just cross your legs and dolphin kick. You can even use your finless foot to hold the strap of the foot with the fin. Good to know.

Which is why new open water divers might want to get some experience in relatively shallow water. We humans get task loaded sorting out new and novel problems. Once divers have some experience solving problems under water, they are less task loaded. In shallow water, you can always CESA on a single breath.

So... are you ready to solve problems at 100' ?

On my Advanced Cert I lost a fin at 65' and continued down to 105'. Remained calm did the one fin swim and did fin. I do not recommend going 100' unless you are with a Instructor or at least Rescue Diver that can help you if you have any issues. Panic is the number one killer of divers.

 

[Freewillow]

Obviously.

But as CESA is a CONTROLLED Emergency Swimming Ascent. That means you don't ascend fast. You should have learned that en-route to getting your DM qualification.



You kinda just made this up, didn't you?



Something else you just made up.

While I perfectly can accept divergences of opinions, I cannot tolerate to be accused of bad faith and lying.

I have seen enough "CESA" that were practiced at too high speed, and I continue to think that this is potentially dangerous.

There is a 30+ pages discussion that confirms my affirmation on the subjet. Unfortunatelly my sources are in french. They can be found here. So, do not try again to call me a liar .

I read your statistics. I am a scientist myself and I must tell you that studies that have been made almost 25 years ago are a bit - irrelevant . New data should have been published since then. If I have the time, I will put them here.

As a reminder, I said that to write to a NEW diver that was afraid to dive down to 100 feet , to try CESA at that depth WAS REALLY NOT A GOOD IDEA. The author of the treath is OWD and has 25 dives @ a maximum depth of 60 feet . GIVE ME A BREAK

 

[DevonDiver]

Unfortunatelly my sources are in french. They can be found here. So, do not try again to call me a liar .

I read your statistics. .

Firstly, they aren't my statistics. DAN and SPUMS are both published on the subject. If their stance changed, then further publications would be released. They have not been, because no change was needed.

You said..."in a lot of countries, most dive docters have asked...." That's blatantly not true. Dive doctors tend to follow the guidelines of DAN, SPUMS and other global or regional bodies. As they share studies etc, most of these agencies concur on issues like this.

I know quite a few diving doctors, in quite a few countries. None have ever expressed concern over the use of CESA.

CESA is practiced up to a depth of 9m. That's supported by the dive medical bodies.

In practical application, it's pure idiocy to suggest that "CESA be removed from large depth". If someone needs to conduct a CESA, then it's their decision to do so. What else are they supposed to do?? Hang around and drown???

You don't seem to comprehend the very simple premise that CESA is only for when you have no other gas to breathe.

Yes... you can carry a pony cylinder, or even dive doubles. That mitigates much risk from running out of gas (prevention). CESA is for when you have no gas supply. Don't think, for one second, that a diver cannot lose their gas supply, even with redundancy or spare gas cylinders. There needs to be a resolution for instances where prevention has failed. CESA and Buoyant Ascents are those two resolutions.

You said..."a lot of Accidents - some of them leading to deaths - have been observed because of the training of this technique". Again, that's blatantly not true. I provided a study which illustrated a 0.00087% fatality rate when CESA has been conducted. That, my friend, is not "a lot"....

You said..."Proper dive techniques make CESA an obsolete and dangerous solution". I'm assuming that's your statement, not a guideline that your quoting or referencing. You fail to understand that proper dive techniques are for avoidance of out-of-gas situations. There still needs to be a solution for if/when an out-of-gas solution occurs.

You said..."There is a 30+ pages discussion that confirms my affirmation on the subjet. Unfortunatelly my sources are in french. They can be found here". That's a discussion group... a forum... just like Scubaboard. It's not an authoritative reference or a 'source'. it's a bunch of divers waffling their views, just like here. As a "scientist", I'd have thought you'd know how to cite an authoritative source or study. That's surprising...

 

[CuzzA]

CESA or BESA at any depth could be dangerous, but being OOG for whatever reason (could be no fault of the diver) and NOT knowing how to reach the surface will in fact be deadly every single time.