padi ow, why is CESA recommended to 9m?

[Zen1300]

In my OW class we did CESA in a pool from 15' of depth. I found the skill to be fairly simple and achievable. In my refresher course last week (been out of diving for a couple years), I had to swim horizontally just under the surface. It was more difficult than I recalled and I actually snatched a breath two feet from the end and had to do it over.

I thought my tank was turned off for the skill in OW, but I cannot recall. I know we did some skills where we had to experience the OOA when a tank was turned off.

My problem with CESA training and skills test is that it's done from a "starting line" and "deep breath." That's not what we will experience down below in the real world.

I would expect that I just exhaled and realize that I have no air, then looking for my buddy in panic mode for air (a few seconds), then going to CESA if buddy air is unavailable. Performing CESA after an exhalation is going to be more difficult than on a full breath for sure. So how practical is the skill?

In an event where air is not flowing as freely, I would thumb the drive and begin going up before experiencing the OOA emergency.

 

[Hawkwood]

...

I thought my tank was turned off for the skill in OW, but I cannot recall. I know we did some skills where we had to experience the OOA when a tank was turned off.

...

It wasn't turned off for the CESA, but you did have it turned off for two exercises: one simply to experience it; and, the second to do an alternate air share swim and ascent.

 

[boulderjohn]

My problem with CESA training and skills test is that it's done from a "starting line" and "deep breath." That's not what we will experience down below in the real world.

I would expect that I just exhaled and realize that I have no air, then looking for my buddy in panic mode for air (a few seconds), then going to CESA if buddy air is unavailable. Performing CESA after an exhalation is going to be more difficult than on a full breath for sure. So how practical is the skill?

You should have a warning in a real situation. In theory, that is why you had the air shut off twice--so you would know what to look for as a warning. In my experience, though, it does not work as well in that exercise as it is supposed to because the air just goes off. That is largely because there is a difference between a tank being shut off and a tank getting down to empty. Your last breaths in a real OOA situation should be a bit more labored than the ones before. You should have a chance to wonder what's wrong, check your gauges, think OMG!, take a breath, and do something.

In technical diving, I have taken stage bottles down to near empty before switching to another tank. My buddy and I once breathed oxygen tanks down to zero while we were driving on our way to a mountain pass to give ourselves an added measure of safety before he ascent. In all cases, I felt a clear sense that it was getting harder and harder to breathe before it was actually over.

 

[pdhenry]

When you're actually doing a CESA the air in your lungs expands as you make your way to the surface, resulting in the ability to continuously exhale for longer than when you simulate a CESA in the pool.

When I did the CESA from 30 feet during my OW dive I was surprised how I didn't run out of air even though I was exhaling slowly the whole way up.

 

[vman]

In my last OW dive the instructor told me to do a CESA from 30 feet (in the ocean, full tank, reg in mouth). In recreational diving scenarios, lets say you are lost, or buddy is missing and you are OOA..what are you supposed to do??? CESA makes sense and I think every OW student should learn this skill.

 

[beanojones]

In my OW class we did CESA in a pool from 15' of depth. I found the skill to be fairly simple and achievable. In my refresher course last week (been out of diving for a couple years), I had to swim horizontally just under the surface. It was more difficult than I recalled and I actually snatched a breath two feet from the end and had to do it over.
.

When I did the CESA from 30 feet during my OW dive I was surprised how I didn't run out of air even though I was exhaling slowly the whole way up.

And this is why CESA is so hard to teach. * (Especially in a Pool)

Add to the fact that as the students exhale swimming horizontally they are actually going to be sinking from the loss of buoyancy from beathing out the air in the lungs, and frankly OW students will tend to see CESA as near impossible unless we instrcutors are pulling the students along and adding air to their bcd for them as they swim.

The fact is, it is the expansion of air in the lungs, and little else, that makes the whole exercise possible. And this only happens on ascent, not horizontally. I cannot exhale continuously for three minutes as I do a CESA from 100 ft/30m because I have some magical powers, but rather because simple physics works that way.

Now granted, starting deeper means that the quick doubling of volume that happens from 10m to the surface is not there, but then again, people diving to 30m should be that much more in control of things anyway.

*If this was the instructor's forum, then I would go through the complete list of ways I have seen CESA 'taught', but it is not the instructor forum. Suffice it to say that String's take that getting rid of the CESA (at least as PADI currently presents it) is not at all a bad idea, given what actually happens in the real world with teaching CESA. There is a reason why very few people have any confidence in doing it or teaching it when PADI is missing the point of how a CESA works.

 

[Zen1300]

The physics makes sense to me, and as a new diver I must trust it... and perhaps test it in training when at a lake...

I believe that my cert has given me the privilege of getting more experience. I don't feel it makes me a competent diver. It is something I now have the basics to continue learning, to seek further guidance, further practice.

I recall the change in breathing when my tank was turned off. I don't have experience in other OOA situations that might cause an immediate lack of air.

I know in my recent refresher, I discovered that it takes time to not get hyper-focused on the "skill." For example, when doing the "find your regulator" task, I became hyper-focused on finding it, rather than just grabbing my secondary. I kept my stream of bubbles going, but didn't grab the reg (swept the wrong way - stupid mistake). It then seemed very odd that one would even attempt to find the primary when the secondary is hanging on your BCD.

Do other training agencies pull these skills together differently than PADI? Guess that is a different thread, perhaps one already covered.

 

[kafkaland]

I found the open-water CESA in OW training useful. It was quite impressive to feel the air expand as I ascended, and be able to exhale for so long. If anything, it really drove home the message of 'never hold your breath' just by feeling how much air you actually have in your lungs at depth. And I definitely have the confidence of being able to do it from moderate depth if I had to in an emergency. The horizontal CESA in the pool lacked all of that - it's just a breath hold swim without any aha moment.

 

[dumpsterDiver]

And this is why CESA is so hard to teach. * (Especially in a Pool)

Add to the fact that as the students exhale swimming horizontally they are actually going to be sinking from the loss of buoyancy from beathing out the air in the lungs, and frankly OW students will tend to see CESA as near impossible unless we instrcutors are pulling the students along and adding air to their bcd for them as they swim.

The fact is, it is the expansion of air in the lungs, and little else, that makes the whole exercise possible. And this only happens on ascent, not horizontally. I cannot exhale continuously for three minutes as I do a CESA from 100 ft/30m because I have some magical powers, but rather because simple physics works that way.

Now granted, starting deeper means that the quick doubling of volume that happens from 10m to the surface is not there, but then again, people diving to 30m should be that much more in control of things anyway.

*If this was the instructor's forum, then I would go through the complete list of ways I have seen CESA 'taught', but it is not the instructor forum. Suffice it to say that String's take that getting rid of the CESA (at least as PADI currently presents it) is not at all a bad idea, given what actually happens in the real world with teaching CESA. There is a reason why very few people have any confidence in doing it or teaching it when PADI is missing the point of how a CESA works.

Have you ever done a CESA from 100 ft? I would love to see video of a typical scuba diver doing a 3 minutes CESA from any depth. Does anyone, anywhere have a video of this?

 

[flots am]

Have you ever done a CESA from 100 ft? I would love to see video of a typical scuba diver doing a 3 minutes CESA from any depth. Does anyone, anywhere have a video of this?

100' CESAs are usually a lot faster than that, and have a lot less "C", which probably accounts for the low rate of survival and the lack of videos.

If you want a video you should find one of those morons that make it to prime-time with the phrase "Hey! Watch this!"

flots.