Is it time to sink the CESA?

[DevonDiver]

It's not really 'cheating' if you have to breath on the 'simulated' CESA ascent... but it would mean a re-take...until you can prove that you've reached the standard.

 

[gcbryan]

Not particularly - an instructor will stop an ascent if a student diver holds their breath, reducing the chance of lung over expansion injury.

A cheater may well be a cheater, but how do you know if they cheated? The scenario you present - an instructor at the bottom, a Dm at the top..... well there's simply no way to determine whether the student has met the performance requirement for the skill.

Are you suggesting that they should "pass" on the basis of no evaluation? Why have the skill at all if you're not going to evaluate it?

The original context was not requiring CESA because it was hard on the instructors ears or some such reason. I think it should be required and would prefer an instructor to do their job and be there but if the choice is to not teach the skill or to teach it and not perfectly evaluate it then I'll chose the later.

The important aspect of all training is the experience not the evaluation or grade. It may be necessary but it's not the reason for learning and experiencing the skill in the first place.

If it hurts your ears to the point of not wanting to teach CESA then still give the student the opportunity to do a CESA and evaluate as you can.

Really, since I'm not an instructor I was just being considerate. I don't really care if it's tough on an instructor's ears. Maybe instructing is the wrong career for someone with pressure sensitive ears. My only real point and opinion is that experiencing CESA is valuable for a student in a class-like setting.

 

[jscott099]

As a warm up to my Rescue Diver courses, I have the studetns perform a variety of self-aid skills, including a CESA. The students are all over the board from brand new to years of experience.

With about 120 rescue diver students under the belt, sadly only 1 in 20 even approach performing the skill accurately without re-training or coaching. Almost all fail to orally inflate on the surface.

It makes me wonder if this is really sinking in. I have yet to find even one student who has even practiced or used the CESA after certification.

 

[gcbryan]

As a warm up to my Rescue Diver courses, I have the studetns perform a variety of self-aid skills, including a CESA. The students are all over the board from brand new to years of experience.

With about 120 rescue diver students under the belt, sadly only 1 in 20 even approach performing the skill accurately without re-training or coaching. Almost all fail to orally inflate on the surface.

It makes me wonder if this is really sinking in. I have yet to find even one student who has even practiced or used the CESA after certification.

So what happens, do they all drown? Disconnect their BC hose before the drill and they'll probably oral inflate.

 

[Soggy_Diver]

I'm not an instructor, but I am interested in teaching and learning in general. So here are a couple of thoughts and a question.

I think that it is predictable that many students have trouble with the CESA. It seems to require that people combine at least three skills. To combine different skills, people need to learn each one to the point that they are automatic, but realistically, in a BOW course, they probably don't get enough practice in any one of them to get to this point.

One skill is controlled exhalation. Unless students swim a lot, (or play a wind instrument), there is no reason that they would have the experience to do this. I wonder if it would be helpful to start off by getting students to take a breath, duck under water, and breathe their air out over 30 seconds, just to get a sense of the timing. I bet a few would find this challenging and need some repetitions.

Then the CESA complicates this with a second skill, having to swim and do a controlled exhale at the same time. In my rescue course, I noticed that some students couldn't do the horizontal CESA practice in the pool, and many just scraped by with some stress and effort. So it is not surprising that divers fall apart when they have to transfer this to a vertical CESA. Rather than giving students a pass for one marginal execution of a horizontal CESA, maybe it would make more effective to have them overlearn the horizontal CESA--do it correctly, then do it several more times so that it is "overlearned", to provide some buffering against forgetting and losing it under task loading.

The third skill is a controlled ascent. Students practice controlled ascents in the pool in BOW, but that is totally different from doing one in open water, from three times the depth, possibly in highly buoyant cold water gear and heavy weight belt, maybe in poor viz or blue water with no visual reference. It seems to me that there is a contradiction in the sequence of skills here. On one hand, students are expected to CESA in BOW. But as I recall, even in AOW, we were discouraged from ascending without a visual reference such as a rope or the bottom. I liked to practice ascending without holding the rope, but one of my instructors actually swam over and stuck my hand on the rope to discourage this. I suspect that most people really learn controlled ascents after AOW, or never. But if students are going to CESA at a controlled speed, they would seem to need the controlled ascent skill. But now for a naive question: How fast can a student ascend in the CESA and still pass?

Just my 3 cents worth.

 

[DevonDiver]

I think that it is predictable that many students have trouble with the CESA. It seems to require that people combine at least three skills. To combine different skills, people need to learn each one to the point that they are automatic, but realistically, in a BOW course, they probably don't get enough practice in any one of them to get to this point.

There are 2 aspects to the ascent...

1. Swim slowly upward.
2. Maintain a slow exhalation (normally by making an 'aaahhh; sound)

The way I teach this is...

Firstly, I get my students good at performing normal ascents. Look up, raise LPI, fin to ascend at the given speed. This is practiced in confined water and then on dives 1 and 2 of the OW course.

Secondly, I get my students good at performing a continued exhalation. This is practised in confined water (the horizontal CESA) and on dry land (everyone sitting around with a watch, saying 'aaahhhh' for 30-60 seconds).

When the time comes to perform the actual CESA ascent (I introduce it on OW dive 3). Then they simply have to put together the two skills... a calm, slow ascent (as they normally do) plus the continued exhalation.

The biggest problem that some students have, is too over-think and over-complicate the process. I try not to 'over-brief' the skill...and this seems to make their (and mine) practice easier.

One skill is controlled exhalation. Unless students swim a lot, (or play a wind instrument), there is no reason that they would have the experience to do this. I wonder if it would be helpful to start off by getting students to take a breath, duck under water, and breathe their air out over 30 seconds, just to get a sense of the timing. I bet a few would find this challenging and need some repetitions.

Sit in a classroom. Look at your watch. Say 'aaahhh' for as long as you can. Repeat until you can manage to do it for 60 seconds.

Repeat this in confined water, whilst swimming horizontally.

Repeat this again in open water, whilst swimming vertically.

Then the CESA complicates this with a second skill.... So it is not surprising that divers fall apart when they have to transfer this to a vertical CESA...... maybe it would make more effective to have them overlearn the horizontal CESA--do it correctly, then do it several more times so that it is "overlearned", to provide some buffering against forgetting and losing it under task loading.

Repetition is a great way to develop ingrained skills.

The other important aspect, is to make sure that the students understand the concept of the skill. If OOA, it is a no-brainer that you need to get to the surface due to no air ...this is pretty much 'hard-wired' into our fight-or-flight reactions. Hence, why panicked divers 'bolt'. All we are really adding to this is the need to go slowly and exhale.

The third skill is a controlled ascent. Students practice controlled ascents in the pool in BOW, but that is totally different from doing one in open water.......It seems to me that there is a contradiction in the sequence of skills here.

The CESA cannot be done until at least OW Dive 2. Which means that they have had chance to perform real OW controlled ascents. However, most (prudent) instructors will not introduce the skill until, at least Dive 3. (also because Dive 2 contains an AAS ascent and a normal ascent.... who wants 3 ascents on a dive?)

I do CESA on dive 3. It then gives me the option of a re-take on dive 4, if they screw it up the first time.

On one hand, students are expected to CESA in BOW. But as I recall, even in AOW, we were discouraged from ascending without a visual reference such as a rope or the bottom. I liked to practice ascending without holding the rope, but one of my instructors actually swam over and stuck my hand on the rope to discourage this.

The practice of different ascents is stipulated on PADI OW courses.

Dive 1. Ascent (usually under instructor control and/or on line)

Dive 2-4. Ascent (usually under instructor control and/or on line)
Using the five point method, ascend at a rate no faster than 18 metres/
60 feet per minute while maintaining buddy contact.

Plus also, the additional skill of... Ascend properly using an alternate air source as either the donor or receiver and establish positive buoyancy at the surface.

Five point ascent. The emphasis during ascent is on maintaining buoyancy control, maintaining a proper ascent rate and maintaining buddy contact. It’s recommended that the ascent follow the bottom contour, line or other reference that helps student divers gauge and control their ascents.

Emphasize that they should not ascend faster than 18 metres/60 feet per minute. If appropriate, you may have them pause at 5 metres/15 feet for a safety stop and/or to listen for boats and regain control of the ascent.

The instructor's decision on whether to conduct the ascent with a line, using only a visual reference, or with no reference, is generally dictated by their overall risk assessment (viz, current, boat traffic etc).

I always try and expose my students to the largest variety of possibilities. If possible, I conduct my courses as follows...

Dive 1 on the line.
Dive 2 AAS Ascent is a free ascent.
Dive 2 normal ascent on the line
Dive 3 free ascent with visual reference (I demonstrate DSMB deployment and ascend with that)
Dive 4 Ascent on line, showing tactile method for determining/controlling ascent speed.


When you progress to AOW training (especially the deep dive), it is totally beneficial to stress to divers the safety advantages of controlling and measuring your ascent by using an appropriate line.

How fast can a student ascend in the CESA and still pass?

This is determined by the respective agencies maximum ascent rates. A max ascent rate is a max ascent rate.

PADI is 18m per min. Other agencies have slower rates.

However, even when teaching PADI courses... I tend to be controlled by my computer (10mpm)... so my students get trained to ascend at a slower speed than stipulated. In the assumption that they will exceed this in a real emergency, at least the training should keep them nearer/below the max.

 

[Thalassamania]

... When students struggle with 6-9m CESAs, I always get them to think about how it would be to perform that from 18m or 30m or 40m..... I then can compare it with conducting an AAS....

If a student is struggling with a 9m CESA (that's only 30 seconds on ascent) I really have to wonder about their readiness to dive, I would never consider certifying such a student. Would you certify a student who could not do something that was, in your words, "It's pretty damn easy."? ...

I don't think I (or anyone else) has ever mentioned anything about students "struggling with a 9m CESA"....

I guess I'm a bit confused.

 

[String]

Id love to see bolt n pray ditched from the syllabus like more and more agencies are doing. Its an ancient relic and not of any relevance to the modern world.

If a student has been dul enough to (i) lose their buddy and (ii) then run out of air as well would makes anyone think the CESA is going to be calm, controlled and within safe speed limits or even exhaling constantly? We're talking eyes bulging last ditch panic here - its not going to end well.
It also encourages people that "its ok to bolt for the surface". The preference for teaching this over buddy breathing i find laughable - if there's a working source of gas on the bottom then use it!

Although the DCS thing is an issue its the ear problems with redescending that messes up courses especially in the 1 instructor with multiple students scenario which is common. Ive seen it before when planned for dive 1 of a day but students unable to redescend to continue that dive thereby wasting half a day of the course.

 

[TSandM]

From somebody who still remembers what it was like to be an OW student, I'd say that, if you are going to teach CESA at all, the student needs to have done it vertically. It's a very different experience from the horizontal swim in the pool. I still remember being somewhat astonished at the fact that I could exhale continuously for that long.

I think I've seen a handful of reports here of people who have had OOG issues and done a CESA -- most recently, a spearfisherman who got entangled and doffed his gear and CESAed, and survived. So, albeit a rarely used skill, it appears to have saved a few lives.

Personally, I'd rather see the time spent on teaching some kind of rational approach to gas management, and on buddy skills, but that's me.

 

[Interceptor121]

I do the CESA as first dive of the day actually it is the second skill after the students have done the surface swim with compass to the line.
The worst part of the multiple CESA is on your ears. In fact as you have been down just few seconds it is difficult to get to a point in which you have any significant nitrogen build up to trigger DCS. This of course if you don't have 8 students and they all fail the skill a number of times.
For what concerns the ear issue it is all about controlling the speed of ascent and descent. All commercial computer trigger an error at 12 meters per minute or so while PADI suggest a maximum of 18 meters per minute which would mean the computer starting to tell you to do decompression stops quite soon however that is a condition due to the fast ascent on its own not to the nitrogen build up.
Personally I would find it quite useful to have a device to tell me if I am exceeding 18 meters per minute. I have taken the approach of not taking the computer on the dive as well as taking it.
With the computer I get a mandatory safety stop initially of 4-8 minutes that actually disappears but I have a way to monitor the speed. Without it is quite difficult.
I have had student doing the skill without even exceeding the 10 meters per minute and other that would do it find and then fail to orally inflate.
In terms of ditching the skill I just wonder how a diver of average experience would not panic before thinking of doing a CESA. However I agree that at least 3-4 options to ascent should be taught and obviously ditching the weights is not an option...