SSI Emergency buoyant Ascent : Training Video

[L13]

First of all PADI does not do this exercise. They do the CESA, but not the buoyant ascent.


For PADI, this is done twice in the pool, and this description is what is supposed to happen. In my DM and AI days, I played the student in many a demonstration of this, and it never happened that way once. Every time it was done, I was breathing just fine and then got nothing at all. There was no warning. In contrast, when I have breathed tanks down (intentionally), the last breaths are indeed harder, and it is usually more than 2 harder breaths. The purpose of this is to teach the student to recognize that the feeling of a tank running low so the student can take appropriate action prior to running out completely. That action could be a direct ascent to the surface. Done at the first realization that the tank is running low, a diver should be able to make it to the surface without running out of air at all. That happens when a tank is running low; it does not happen (at least in shallow water) when a valve is turned off.

Is it possible that with older valves it takes longer to turn the air off, causing the difficult breaths before the end? I know some valves take significantly more turns to go from full on to off than others. Maybe the same result can be produced by closing the valves more slowly.

 

[boulderjohn]

Is it possible that with older valves it takes longer to turn the air off, causing the difficult breaths before the end? I know some valves take significantly more turns to go from full on to off than others. Maybe the same result can be produced by closing the valves more slowly.

For a while as an instructor I achieved the desired effect by very nearly shutting the valves, leaving them open just a crack.

 

[quietlife4me]

as a new diver going through OW certification at the moment....I found the "this is what it feels like when out of air and you have a reg in your mouth" simulation depicted in this video to be extremely helpful. The instructor can say "you don't need to panic" all they want...but when you can actually experience it in a controlled situation, my brain was able to actually convince itself to be true.

On a purely logical/experiential/etc perspective...I found it fascinating. Probably not that fascinating to the experienced diver though.

 

[wetb4igetinthewater]

as a new diver going through OW certification at the moment....I found the "this is what it feels like when out of air and you have a reg in your mouth" simulation depicted in this video to be extremely helpful. The instructor can say "you don't need to panic" all they want...but when you can actually experience it in a controlled situation, my brain was able to actually convince itself to be true.

while not a skill, it is an important experience in a controlled environment, hence done in confined water.

On a purely logical/experiential/etc perspective...I found it fascinating. Probably not that fascinating to the experienced diver though.

No it isn't. I have only run out of gas once, and that was when I was a DM candidate working on my mapping project. I had placed DSMBs to mark various sites, and I had less than 200 psi in my cylinder when I went to retrieve the last one.

 

[sea_ledford]

Hand signals were:

• You
• Look at me
• Out of air
• Drop weights
• Go up
• Ok?
• Unknown arm tap - DM (#2) or Dive con I guess since its SSI
• Other diver look at cameraman diver - watch students
• ok - Confirmation that the DM will watch the students while instructor demonstrates
• Lift up BCD inflator
• Neutral Bouyancy
• You.
• turn valve
• Unkown signal - cut off
• ok
• look at SPG
• out of air
• Uknown hand-signal - pull weights
• Unknown hand signal - grab inflator hose
• Point at surface
• Look up, breathe out
• Ok

I would think an instructor had explained the entire process on the surface at least once or twice. And then what you see here is a similar explanation with hand-signals or visuals as they do the skill they're demonstrating.

The hand-signals are not something you'd see in normal diving. Perhaps out-of-air, or go-up. The rest are just an attempt to communicate a fairly lengthy concept to a student underwater, which the student should already understand, but this is a sort of repetition.

My best guess for hand signals. Made sense to me, but I teach a lot of DM classes, so I'm good at figuring bad signals out on the fly!

 

[rick00001967]

ya the signals are certainly exaggerated in that video for sure.

as someone stated above, turning off the air is something our shop did to simulate how it might feel to run out of gas.

it was a good observation btw that they also pointed out the diver went up alone. the instructor must be in contact at all times during these excersises. but for the purpose of the video, i assume they were only trying to show what the diver should be doing.

as far as being out of control on ascent.....well thats the trouble with an emergency buoyant ascent. if you drop your lead, you will have no control. it should only be a last resort reaction. a controlled swimming ascent (shown in the second video) should be the primary ascent method if you had to surface alone in an emergency.

 

[rick00001967]

just curious.....why the emergency ascent? did you both run out of gas in that 6 minutes?

 

[rick00001967]

Unfortunately I had to do an emergency ascent during a dive in Cozumel last February. Luckily it was 6 minutes into the first dive of the day. Ripping downcurrent on Punta Tunich wall swept a companion down the wall and we were at 120 feet in the blink of any eye. I was able to reach her and then did the emergency ascent. Not a fun dive.

just curious.....why the emergency asecent? did you both run out of gas in that 6 minutes?

 

[johndiver999]

I have seen ONE instructional outfit/DS do proper training of what it feels like to run low/out of air.

They manifolded a small pony bottle with a big tank. The instructor controlled the rig, he carefully decanted maybe a 50-150 psi to the pony then shut the main tank off. The student then had a chance to breath the pony down in the pool. Of course, depending on the size of the pony, the drop off in pressure and increased resistance is quicker with the pony, but it does give the student a decent feel of it.

The other obvious thing is to purge the tanks down at the end of the pool session until they are at 50 psi and then have the student actually breath the tank down to zero (while safely on the pool deck).

Shutting the tank off underwater completely is hardly equivalent, although if the instructor was using the student's octopus, I bet he could make fine adjustments to the tank valve to make it just a little hard to suck, but the adjustment varies with different tank valves (and probably tank pressure too).

 

[Guitarcrazy]

My friend had just been certified and this was her first dive after OW training. The DM thought a deep wall dive would be good for her. We didn't know this was the site until right before dropping in. She was swept down the wall and went from 40' to 100' in a matter of seconds (30 seconds or so I would guess). I was able to reach her (the DM did not go after her) and grabbed her bed. My computer started alarming as we were at 110'. We kicked as hard as we could and then we were at 120. At that point I started filling her bed in hopes it would be enough to arrest the descent. If not I was going to ditch weights. We did start ascending, and at that point I tried to dump air but we went to the surface anyway. The entire group was spit out eventually and we were all spread out quite wide on the surface. Luckily it was so early in the dive nobody was bent. I told them I would not be diving with that DM again.