CESA theory

[Blackcrusader]

I would very much appreciate receiving your manuals

Well a few pages at least. Dodi these were from BSAC 1986 manuals I had. So you can see different agencies have different coverage of materials and training. By the way, the emergency ascent is only taught in theory it is not to be practiced.

You can buy recent manuals online. Digital training materials

 

[John C. Ratliff]

Let me give you a few experiences and a bit different perspective than may have been provided here so far. I have been diving since 1959, and went through the U.S. Naval School for Underwater Swimmers (USS) at Key West, Florida in 1967.

I took my first scuba course in 1963 from Roy France, who was an LA County instructor. We, in our open water checkout in Yaquina Bay, Oregon, did a Controlled Emergency Swimming Ascent from about 35 feet, again with no problems.

During our USS training, part of that was a buoyant ascent from about 30 feet. They had a dome underwater that we started from, poked our bodies out of it and gripped the side until the instructor had filled our life vest. At that point, we had an instructor beside us, and were told to "blow and go," release and head for the surface. If we did not do the "blow and go" part, the instructor was there to punch us in the stomach to make sure we blew out all our air. We all survived without a problem. This was to simulate an escape from a submarine.

Go forward a decade and a half, and I was working on underwater clam bed surveys in Yaquina Bay, and photographing divers at work. I had done one other dive, to about 35 feet, and was at about the same depth (in 1975), when I ran out of air. I went over to one of the other divers, did a few buddy breathing breaths, then moved off and took more photos. I came back, got a few more buddy breaths, and repeated that until I was out of film. I then simply told the divers with hand signals that I was headed to the surface, and did so. I blew out continuously, and had no problem at all getting to the surface.

I have no problems doing CESA from just about any depth. I don't worry about decompression sickness, as I don't go near the "knife edge" of the no-decompression tables.

SeaRat

 

[Blackcrusader]

I am not talking about OOA due to lack of air in the cylinder

Agree on the (lack of) choice. But it does not hurt to try to understand what happens in your body, physiologically. Or explained differently if you have a chance to do it in a controlled manned or just surface as fast as possible.

You also need to account for what happens to your mind and mentality. Will you panic before you get to the surface thinking you won't make it? There is also the buoyancy assisted ascent where you can still use your BCD for lift ( you can also drop weights ) and as the air also expands in your BCD your ascent speed needs to be monitored. Your BCD purge valves will release air should the BCD be over inflated but your lungs will not so you need to be hmm sing or scream to make sure you release expanding air from your lungs.

Again back to your original post if you have air in your cylinder and your tank valve is working then you are never really OOA in the first place.

 

[Bob DBF]

A Controlled Emergency Swimming Ascent is traditionally done at 60 fpm, or as close as possible. It can be done from recreational depths. I did quite a few back in the day without an SPG or j-valve (or the valve was tripped), before I learned how long a tank lasted. Most of the time I got a couple of breaths on the way up, without those breaths it was a bit harder as there weren't BCs either and one had to swim up.

A buoyant ascent is what the Navy Submarine Service still trains for, although the training tanks aren't the same as in the film, the training is. The reason for having no air in the the lungs to start with is the speed to the surface expands the air rather fast, and they are worried about overexpantion. Although in training there is no worry about the bends, in real life there will be bottom time while operating the lock and exiting the sub from whatever depth. A few minutes at 200' or 300' may have a deco obligation.

Buoyant ascent can also be done in SCUBA as a last resort, however the tables are based on a 60 fpm ascent, so the chances of being bent go up.

Over the years I've done all three.

 

[wetb4igetinthewater]

A Controlled Emergency Swimming Ascent is traditionally done at 60 fpm, or as close as possible. It can be done from recreational depths. I did quite a few back in the day without an SPG or j-valve (or the valve was tripped), before I learned how long a tank lasted. Most of the time I got a couple of breaths on the way up, without those breaths it was a bit harder as there weren't BCs either and one had to swim up.

A buoyant ascent is what the Navy Submarine Service still trains for, although the training tanks aren't the same as in the film, the training is. The reason for having no air in the the lungs to start with is the speed to the surface expands the air rather fast, and they are worried about overexpantion. Although in training there is no worry about the bends, in real life there will be bottom time while operating the lock and exiting the sub from whatever depth. A few minutes at 200' or 300' may have a deco obligation.

Buoyant ascent can also be done in SCUBA as a last resort, however the tables are based on a 60 fpm ascent, so the chances of being bent go up.

Over the years I've done all three.

How people who started a long time ago had to train for the way they dived due to the equipment they had is so different that today.

Most people certified today likely couldn't handle the amount of mental toughness required.

 

[dmaziuk]

60 fpm from 120 feet is 2 minutes, any competent swimmer should be able to do it even if the last 30 seconds won't be pleasant.

Submarine escape is something else.

 

[Bob DBF]

How people who started a long time ago had to train for the way they dived due to the equipment they had is so different that today.

It isn't so much the equipment was different, there just wasn't as much. One good thing was that without a BC there wasn't a lot of overweighted divers.

Submarine escape is something else.

Unless it's for real, it's great fun.

 

[John C. Ratliff]

How people who started a long time ago had to train for the way they dived due to the equipment they had is so different that today.

Most people certified today likely couldn't handle the amount of mental toughness required.

What most people don't realize is that it isn't "mental toughness" that is required, but relaxation and knowledge that we have the ability to deal with these situations. It has to do more with being comfortable in the water, and any thought of "toughness." It seems that we are allowing people into scuba who simply are not comfortable with being underwater, or even in the water. That means that with a simple problem, they are pushed over the edge mentally.

When I took my first scuba course, I had already been diving three years. I had been a member of the North Salem High School swim team. I had gone through the YMCA Lifeguard training. I had been snorkeling since I was in grade school. We no longer see many of these types of people coming into scuba diving.

I remember having to do a "jellyfish float" on the surface for 10 minutes during my YMCA lifeguard training. It got boring, to the point where I experimented with capturing a bubble in my eye socket (we had no goggles at that time, nor a face mask) so as to be able to see clearly through one eye. We could only capture a bubble under one eye, as if we moved our face more to get both eyes, one bubble would be lost. I mention this to simply show how comfortable we were in the water, face down, holding our breath for 30 to 45 seconds before raising our head to get a new breath, and doing that for a full ten minutes.

I feel it is a fallacy to say that the ability to perform in the water was "mental toughness." Rather, it has to do with being relaxed in the water, and thinking through different problems. I had to do that last summer, when my tank slipped out of a new (to me) BCD harness while I was diving. Here's the video I made of how that happened, and how I resolved the problem.


SeaRat

 

[Celt]

"mental toughness" is something that is learnt with practice but toughness is the wrong word. Confidence is the word.

 

[AfterDark]

What most people don't realize is that it isn't "mental toughness" that is required, but relaxation and knowledge that we have the ability to deal with these situations. It has to do more with being comfortable in the water, and any thought of "toughness." It seems that we are allowing people into scuba who simply are not comfortable with being underwater, or even in the water. That means that with a simple problem, they are pushed over the edge mentally.

When I took my first scuba course, I had already been diving three years. I had been a member of the North Salem High School swim team. I had gone through the YMCA Lifeguard training. I had been snorkeling since I was in grade school. We no longer see many of these types of people coming into scuba diving.

I remember having to do a "jellyfish float" on the surface for 10 minutes during my YMCA lifeguard training. It got boring, to the point where I experimented with capturing a bubble in my eye socket (we had no goggles at that time, nor a face mask) so as to be able to see clearly through one eye. We could only capture a bubble under one eye, as if we moved our face more to get both eyes, one bubble would be lost. I mention this to simply show how comfortable we were in the water, face down, holding our breath for 30 to 45 seconds before raising our head to get a new breath, and doing that for a full ten minutes.

I feel it is a fallacy to say that the ability to perform in the water was "mental toughness." Rather, it has to do with being relaxed in the water, and thinking through different problems. I had to do that last summer, when my tank slipped out of a new (to me) BCD harness while I was diving. Here's the video I made of how that happened, and how I resolved the problem.


SeaRat

There is nothing in this post to disagree with. Comfort in the water or being at home in the water is the #1 requirement of scuba diving IMO. Any diving skill can be learned if one is comfortable and able to function without distraction.

I attempted to introduce my wife at her request to scuba many years ago when we had just gotten married. I soon found that although she loved the idea of diving she was much to fearful of being UNDERWATER to learn. After many years of snorkeling she was able to finally make shallow dives with me but never was able truly able to relax once submerged. I would have never even considered trying to teach her CESA.
I often wonder how many people like her are carrying OW or AOW cards?
Mrs.AD would be the classic DM lead diver that nobody would want has a dive buddy.
Don't mean to sound harsh I love her but facts are facts.