I had trouble with the CESA

[Scott]

If you're doing the PADI OW certification, you'll do one CESA for your checkout dives, and it'll have to be from around 30-35 feet deep, I think.

Just to clarify, according to standards CESA is conducted at a depth of at least 6 metres/20 feet but not to exceed 9 metres/30 feet.

 

[boulderjohn]

When I did my cesa in I think 1979, it was from 60 or 65 ft. Left hand held the inflator of my ( borrowed) bcd and second stage was out of mouth in my right hand. Think of h's and not k's or hard c's "ahhhhhh". I think I'm better for it.

It is not taught that way today. The regulator is in the mouth all the way. That is important because if you do run out of air on the way up and try to inhale, you will get some air out of the regulator. If the regulator is not in the mouth, you will get water, and breathing water is definitely not in your best interest.

 

[Splitlip]

I know. Makes much more sense to keep the reg in the mouth. But still the way they taught us going vertical I think is much more appropriate than doing it horizontal.

When I was originally certified, I don't believe we had balanced regs as I was taught as we surfaced from OOA, there would be more air available as we ascended. Which of course we all know to be the case.

Your comments re. J-valves were right on.

 

[boulderjohn]

I
[/COLOR]BTW, we did our freediving practice in the pool while wearing the same weights and wetsuits we wore with the scuba gear. I thought the instructor was crazy. I was surprised that I could still swim easily with the weights on and no tank or BC. It's really only the negative buoyancy of the tank that you have to fin against at the surface while you inflate your BC.

If you are talking about an AL 80, it is not all that negative at all at the beginning of a dive. If you are doing a CESA because you have almost emptied the tank, then it will float. It will actually be pulling you to the surface during a CESA.

 

[Quero]

It is not taught that way today. The regulator is in the mouth all the way. That is important because if you do run out of air on the way up and try to inhale, you will get some air out of the regulator. If the regulator is not in the mouth, you will get water, and breathing water is definitely not in your best interest.

That, plus the fact that the reg may deliver another breath of air as the pressure drops on the way up.

 

[DevonDiver]

As you read this post, sat on a chair in an office/at home etc, take a deep breath...and release....and release...and release...

You can practice the 'timing' for CESA anywhere.

An ascent rate of 18m per minute... 9m/30ft ascent = 30 seconds to maintain an open airway. For an 18m/60ft ascent... it'd be 60 seconds. etc etc

"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh"

As for the physical 'in-water' mechanics of the ascent.... well, it's identical to a normal ascent (except you maintain open airway, rather than breath continuously)..... so, in effect, you're practicing this every time you do a proper ascent at the end of a scuba dive....

Don't over-complicate the skill.... Normal ascent versus CESA - differences highlighted in red...

Normal Ascent:
Breath continuously
Look up
Raise LPI, to enable venting gas during ascent
Raise right arm to protect head on ascent
Kick slowly upwards, venting gas as necessary
Maintain max ascent speed of 18m/60ft per minute
Attain positive buoyancy upon reaching the surface (LPI inflation)

Controlled Emergency Swimming Ascent:
Maintain open airway, via making a noise throughout the ascent
Look up
Raise LPI, to enable venting gas during ascent
Raise right arm to protect head on ascent
Kick slowly upwards, venting gas as necessary
Maintain max ascent speed of 18m/60ft per minute
Attain positive buoyancy upon reaching the surface (oral inflation)

 

[Hawkwood]

Gee, that's what I like about SB. I can learn a new way of thinking about or teaching something just about every day. Thanks Andy!

Bill

 

[jcxd45]

Was it the sensation of running out of air the freaked you out, or manually inflating your BC after all of that?

If it's the feeling of running out of air, you can practice taking a big breath and very slowly letting it out (for 30 seconds) any time you like, until it's not scary any more. And remember that even if your lungs are empty, you don't need oxygen immediately.

If it's manually inflating the BC, that gets easier with practice. Also realize that you're not *that* negatively buoyant without the BC; you can easily fin to keep yourself up for the minute or less it takes to fill the BC.

---------- Post added April 26th, 2012 at 03:22 PM ----------

BTW, we did our freediving practice in the pool while wearing the same weights and wetsuits we wore with the scuba gear. I thought the instructor was crazy. I was surprised that I could still swim easily with the weights on and no tank or BC. It's really only the negative buoyancy of the tank that you have to fin against at the surface while you inflate your BC.

It was definitely the sensation of running out of air that got to me, and then I was in full panic in my mind.

For the record, it was from 25 feet, sandy bottom, reg in.

I panic'd at about 12 feet and took a breath through my reg.

Funny part is that I had spent a huge portion of the night before practicing the breathing...on the balcony at the resort I could exhale for 30 seconds with no air expansion help.

During the CESA, I blew it out way too fast then panic set in....kinda weird since I knew that I was safe the whole time and could just take another breath.

After calming down on the surface, we went back down and I got through it the second time but still ran out of air at about 6 feet.

This time though I just kept trying to blow out and made it.

The instructor said that I also wasn't kicking hard enough on the way up the first time and I know my BCD was too tight to take a full diaphragm breath (lesson learned).

Thanks for all the replies!

John

 

[DevonDiver]

Gee, that's what I like about SB. I can learn a new way of thinking about or teaching something just about every day. Thanks Andy!

Bill

A spectator to my OW class might confuse it, at times, with a yoga or meditation session.... people sitting around the classroom, or on the dive boat, going "ooooooooooooooommmmmmmmmmm" whilst staring at their watches.

I also get them practicing time vs distance on the surface. It's easier to do more repetition (and correction) there, than on the bottom.

End result - by the time they reach the 'CESA check-out dive', they're confident to perform the skill.

Raising the similarities between a normal ascent and a CESA certainly helps prevent student's over complicating/thinking the task. IMHO, over-thinking the task tends to be what causes the most problems for students. K.I.S.S. "Do a normal ascent, as already practiced/perfected, but hum your favorite tune all the way up and remember to orally inflate at the top".

Humming a tune can help... it's less stressful/more fun... and provides a rhythm that can help with gauging ascent rate. Depending on the tune, it could mean one verse per 10m of ascent etc etc

Alternatively...(depending on the age/disposition of the class)... exhalation via an extended....
"fffffffffffffffuuuuuuuuuuuuuuuuucccccccccccckkkkkkkk" or
"IIIIIAAAAAAMMMMMMAAAAAACCCCCAAAAARRRRREEEEELLLLLLLEEEEESSSSSSDDDDDIIIIIIICCCCCCKKKKK....."
....can be equally amusing and get another message across that stresses dive safety and gas awareness

 

[supergaijin]

I second the tune thing- I usually opt for "Raiders of the Lost Ark".

It's easy to breath out or hum a tune while sitting, next step is to practice it walking and then walking at pace.

Unfortunately this is one of the skills that do not get enough time during many OW training courses. I know that in my time in SE Asia working to a 3 day schedule, the CESA was a minimum-standard exercise. Not proud to admit it but there you go.

CMAS 4* by the way have a pretty mean exercise supposedly to simulate a submarine escape with inflated jacket.