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View Full Version : Emergency ascent training -- What depth?



Jim Malone
January 1st, 2011, 10:50 AM
I have been practicing Emergency Ascent for OOA situations.

Drill is to take your second stage out of your mouth (to simulate an OOA and ascend to the surface while blowing small bubbles and within a max ascend rate of 18 meters per minute (60') per minute. (yes i know the regulator schould stay in your mouth, but this way i can't take "cheat" breaths)

I have been practicing these ascends from 25 meters (80 '), and they are suprisingly easy.

You are convinced you will run out of air but there was always enough air inside my lungs to continue to blow bubbles.

I am practicing this to retrain my old 3* CMAS standards (before there was a 4*)
where we had to do this once from 100 feet. ( I am one of those guys who still have their max air depth qualification of 60 meters or 200 feet ( ON AIR!)

Any of your guys engange in similar deep OOA emergency ascend training?

DevonDiver
January 1st, 2011, 12:57 PM
You should not take your regulator from your mouth. I am shocked that CMAS teach this...I don't believe that any other agency teaches that as an approved method for emergency ascent. There is simply NO logic for removing the regulator on ascent.

There's no benefit from taking the regulator out for practice. The purpose of practice is to refine a skill under safe circumstances. Why make it unsafe?

What procedures do you take to mitigate the risks of repeated ascents and/or maintain safe ascent speed?

drbill
January 1st, 2011, 01:09 PM
I have had only one true CESA from that depth range (80 ft). It happened when my dip tube became clogged with debris from inside the tank and stopped all delivery of air through the valve. I had just exhaled and was trying to get another breath, so my lungs were fairly well evacuated. I did NOT find the CESA (about 70 seconds) to be that easy.

Of course you probably had a breath of air in your lungs when you began your ascent. And you may be much younger and in better shape than I was (I was in my late 50s then).

Crowley
January 1st, 2011, 01:30 PM
You should not take your regulator from your mouth.

Very much agreed - and I get asked very regularly about this. It makes no sense whatsoever.

Expanding air in the hoses due to the drop in ambient pressure as you ascend may well get you another breath from the regulator on the way up, so taking the regulator out potentially reduces your chances of success.

I've never had to CESA but I know some people who were trained back in the day to CESA from 30 metres, regulator out, or with the air actually shut off. It's not something I practice but I often will CESA along with my open water students and an old competition between instructors proved we could make 9 metres in 50 seconds horizontally in a pool although of course this did require a big ole lungful of air to start with. Barring some form of equipment failure it's unlikely to happen and in my line of work I might have up to ten people following me - all of whom have an alternate air source, so I don't worry too much. It's rare that I am so far away from somebody I couldn't make it to their octopus.

Cheers

C.

udtfire
January 1st, 2011, 01:59 PM
jim I will say great skills but you are getting older and doing cesa deeper than 30 fsw should be discoraged due to expanding bubble formation if you wis to practice your distance on one breath do it at depth horazonal see how far forward you can swim on one breath and a long exhale
remember outers watch you and you dont even know it should a newer dive mimic your drill does he have the understanding and skill you do or will he just get hurt.
this is not a judgement do as you will but be prepaired to live with your choice have a safe day see you in the water

Garrobo
January 1st, 2011, 02:19 PM
I had been diving about a year and had around 60 dives when I got interested in CESA. I hired a DM and we went out on some shallow reefs and did them. The best I could do was from about thirty feet. Below that I sort of said "**** this." and got some air. I did mine without the reg in my mouth since it was easier and more efficient for me to control the slow exhale in this manner. I never was very good at holding my breath or swimming underwater for much of a distance let alone surface swimming. I suppose that if I was in an emergency situation and couldn't get air from someone nearby I do have the knowledge of how to do it and would probably do my dangdest to get to the surface without drowning. Otherwise..............

Jim Malone
January 1st, 2011, 02:34 PM
It seems my CESA training stemming from the 80's is no longer considered safe :D
And it was done this way in the 80's. Closing the valve was for the die hards, the wimps took their regulator out, because the instructor needed to see you blowing bubbles, not inhaling!
This was old school CMAS training. One of my instructors was "DE SWA" an instructor who was the first 3* CMAS instructor in Belgium. His 3* Instructor card (# 14) was issued in 1969 by Cdt. J.Y. COUSTEAU himself!
The training was done following French navy divers regime. 50 meter apneu's with frequents syncope's, 2 min+ apneu's, running 12 m during apneu carrying 10 kg of lead on the bottom of the pool, breathing with 7 divers from 1 bottle on the bottom. Constructing a mechanical part without mask, and swimming 5 meters back and forth between the bottle and the tool!
Pulling off masks and regulators unexpected, closing your valve behind your back, and even pulling your J-valve so you had no reserve during pool training. For an 16 y.o. it was plain FUN!:D
Ah the time of the Fenzy toilet seat, sharkskin dive suits and big knives! :cool2:

DevonDiver
January 1st, 2011, 11:36 PM
Nowadays, instructors just ask students to make a continous noise (i.e. "aaahhh" sound) to ensure that they don't cheat and inhale during the practice.

The drill is equally effective, but if things go wrong, you're safe.

I've seen other online references to CMAS & removing the regulator for ESA. I wonder if this is still policy or not?

There's a lot of real advantages to leaving the regulator in place during an emergency ascent. You may get some extra air, even a half-breath, on ascent. Also it's better to suck on an empty tank, than to suck on the ocean if/when you do reflexively inhale.

madfishdiving
January 15th, 2011, 06:12 AM
is it essential to teach an emergency ascent in open water sessions (SSI standards) ?

farsidefan1
January 15th, 2011, 07:20 PM
Well yah, now I understand, if it is the way the French taught it. ;)

tstormdiver
January 15th, 2011, 08:02 PM
is it essential to teach an emergency ascent in open water sessions (SSI standards) ?

Teaching by SSI's standards, yes, it is required to teach both the Emergency swimming ascent (in both pool & Open Water) & the Emergnecy buoyant ascent (pool only). When I teach these I teach these techniques with the understanding that these are the least desirable methods to deal with an OOA situation (the most desirable techniques being watching your gauge/ following gas planning to avoid the situation altogether & if there is a need,.. to share air to get to the surface safely) & that it could increase the risk of DCS.

Hallmac
January 15th, 2011, 10:56 PM
Expanding air in the hoses due to the drop in ambient pressure as you ascend may well get you another breath from the regulator on the way up, so taking the regulator out potentially reduces your chances of success.C.

Don't forget that at 30 meters you still have gas in the cylinder, the pressure inside has only equalized to the pressure outside. During your ascent the pressure differential changes, thus your regulator will begin to deliver air allowing you to slow down your ascent and breath all the way to the surface.

That is as long as you don't get stuck with a cylinder like Dr. Bill did or have the second stages open due to one of a few issues. That is when breathing the bag is really an appreciated skill.

Dr. Bill glad you are still with us.


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