Water in regulator at depth causing panic

[boulderjohn]

Here is a somewhat laughable but still telling example of the problem I just mentioned above--teaching differently from the way it is done in real life.

In a real life CESA, you are supposed to control the speed of your ascent. As you ascend and the air in the BCD and the bubbles of your wetsuit/drysuit expand, you will begin to ascend too quickly, and you are supposed to control that by burping out a little air from the BCD. That's what is supposed to happen in real life.

When I took my instructor exam, all candidates had to demonstrate a horizontal CESA, starting at the end of the pool that was about 4 feet deep and ending at a point where the water was about 3 feet deep. We all started neutrally buoyant and swam at a controlled speed for 30 seconds, exhaling all the way. Of course, the gas in our wetsuits and BCDs did not expand, so the only way our buoyancy was changing was by our exhaling for 30 seconds, absolutely emptying our lungs in the process. Of course, all of us hit our knees on the floor at the end, and, of course, we all had a point deducted from our scores for losing buoyancy.

We all passed anyway, so no one asked how the Hell we were supposed to remain buoyant while exhaling for 30 seconds. Talking about it later, we said the only thing we could have done would have been to add air to the BCD--the exact opposite of what we were supposed to be teaching the students to do.

 

[boulderjohn]

It might also be reassuring to students to know in the example above if one had to do a CESA from 130 ft, 40 meters the recreational limit for scuba diving for some training agencies, fully exhaled from 6 liters of lung volume to residual volume of 1.2 liters, the gas would expand 5 times to 6 liters or your original full lung capacity when you get to the surface.

Unless you are doing it at the altitude at which we dive in Colorado and New Mexico. Then it expands even more.

 

[johndiver999]

It might also be reassuring to students to know in the example above if one had to do a CESA from 130 ft, 40 meters the recreational limit for scuba diving for some training agencies, fully exhaled from 6 liters of lung volume to residual volume of 1.2 liters, the gas would expand 5 times to 6 liters or your original full lung capacity when you get to the surface.

Don't try this at home, keep exhaling.

LOL, I think if you want to you know what it is like, stop reading descriptions, stop listening to people who have never done one from depth (even a training one) and do one yourself from 60 feet or something.

I've practiced quite a few from that depth (around 60) and for me, it does NOT provide any reassurance that I would be fine from 130 feet! In fact, it reinforces the opposite idea and as a result, I would be VERY hesitant to dive to 130 without a redundant scuba unit with me. But hey, this is just one more internet diver's opinion.

 

[FishWatcher747]

I've practiced quite a few from that depth (around 60) and for me, it does NOT provide any reassurance that I would be fine from 130 feet! In fact, it reinforces the opposite idea and as a result, I would be VERY hesitant to dive to 130 without a redundant scuba unit with me. But hey, this is just one more internet diver's opinion.

You are preaching to the choir brother.