running out of air

[flots am]

I see some here say they teach it from day one, but is it like that everywhere?

Most of the training materials I've seen mention not running out of air and monitoring your remaining gas, but don't make a big deal out of it; they just cover enough of it to make it difficult to sue.

I cover it using flowery, happy language like "Suppose you were unbelievably stupid and ran out of air, what would you do so that you wouldn't die?"

It's generally an attention getter. although probably not popular with the marketing people, and I don't expect to see those words in the OW training materials any time soon.

---------- Post added October 18th, 2015 at 01:28 PM ----------

We teach that you are to keep your regulator in your mouth in this sort of emergency and that you can expect to get a little more air as you ascend due to the decreasing ambient pressure and the concomitant increase in pressure differential between the tank and the external pressure... yes?

I don't mention anything about "extra" air because it's a crapshoot whether there will be any or not, however I do tell the students to keep the reg in because even if they're not getting air, they're also not getting water.

---------- Post added October 18th, 2015 at 01:29 PM ----------

Either, some other people are correct and it will breath perfectly normal until one last breathe - where air will just completely stop, or am I correct and you will be able to sip the last dribbles of air from the tank as you press the purge.. almost like breathing through a straw..

That depends on if you're OOA because the tank ran dry or because the valve clogged.

There are no guarantees which one anybody will have.

 

[dumpsterDiver]

"Running out of air" implies that the minimum expected air reserve has been consumed - not so difference than when an automobile driver says he "ran out of gas"- it does not imply that a fuel filter became clogged... Obviously a hose could explode at any time and make the unit unusable..

 

[Diving Dubai]

So I've experienced OOA twice

1. In the pool during OW tank being turned off (pre briefed) - Yes the breathing got harder

2. Intentionally sucked my stage (S50) down at about 20m The breathing didn't get harder it was more that I felt that breath had less air - hard to explain. Anyway I could instantly tell something as wrong - actually I knew exactly what was wrong, instinct took over and i switched after that I breath.

Something not covered yet, is what's it feel like to drown?

I have experience of that too.

Long story short, on a dive at 20m in excellent vis (30+M) I took a wet breath. I exhaled to clear, inhaled and nothing. Switched to redundant supply and nothing zero, nada!

At this point even though I could see my buddy I went vertical and headed for the surface.

At this point my lungs are trying to breath but they are getting nothing. So what goes through your mind?

In my case the best I can explain was I was thinking of 3 or 4 things each at the same time all compartmentalised. Imagine reading 4 different columns of print down a page taking in all the information at teh same time.

So my thoughts were:

1 - what a ****ty way to die - last dive on a 20 dive trip
2 what the heck is wrong? Check both spgs (not my AI computer) Each SPG was showing about 150 bar. Dammit why no air
3 It's a bloody long way to the surface
4. What's going on?

At no time did I think to ditch weight - well I wouldn't as i don't carry any, nor add gas to my wing to assist the ascent. I'm finning hard and my lungs are panting, that surface isn't getting closer and my ascent warning on my comp is bleeping quite well

At 10m suddenly I get air - my exhale was so explosive I flooded my mask. What seemed to have happened was that the wet breath caused my epiglottis to shut so no air could get to my lungs and then it opened again thankfully. The whole incident was over in max 30 seconds I guess.

Here's the lesson. I've trained for OOA and practiced and practiced. I've also had other minor issues under water (free flow of LPI was one) all handled just the way I'd trained without drama. The difference was I COULD BREATH!

When you can't breath your body goes into survival mode. There was no panic on my part ( a lot of being pi$$ed at the situation yes, but panic no) I was fixated on trying to resolve why no air from two independent sources (both having been used during the dive so I knew they were on) as well as being fixated on the surface, so I didn't' have the bandwidth to think about inflating my wind a little to get me to the surface a bit faster. Which may explain why divers are found drowned with their weight still attached - not just newbies.

This is possibly a whole different discussion and I don't wish to de-rail this thread, but since we were discussing what the start of OOA feels like I though I'd add what the next part feels like too.

And if anyone wants more detail I'm happy to add - I just wanted to keep the post succent

 

[dmaziuk]

I'm finning hard and my lungs are panting, that surface isn't getting closer

This is particularly unpleasant when you exhale on the way up: you get all the air out and the surface is still no closer than it was back when you had some air in your lungs. BTDT, got that t-shirt, though without the laryngospasm. Eeek.

 

[johngayle]

Read a recent thread regarding running out of air and it lead me to a question I thought I would ask outside that thread.

What are indications that a tank is getting low, other than the gauge, when you are underwater or do you take that last breath and that's it?

I ask about underwater, as I have run out of air after surfacing from a dive while waiting on a boat pickup (drift dive.)
As I recall, although I knew the gauge showed empty, I was able to suck in small amounts of air and the air seemed very dry (or maybe my mouth was just becoming that way.) Always thought that if I experienced that underwater, I would try and get buddy's/DM's attention and signal "out of air" and hope they were ready to surface!

Divers should never run out of Air monitor your pressure guage all the time I HAVE over 2000 dives and have never come close to running out of air its a basic most important thing your do when diving

 

[Neilwood]

Divers should never run out of Air monitor your pressure guage all the time I HAVE over 2000 dives and have never come close to running out of air its a basic most important thing your do when diving

I agree with the sentiment but not the wording- no diver should ever run out of air barring technical problems or emergencies. Sometimes situations put people in circumstances that have not been planned for. Fortunately in OW and diving with a buddy going OOA doesn't have to be life threatening.

 

[bowlofpetunias]

In my opinion, it is better for a student to have some knowledge of what it may feel like if they screw up and get very low on a tank. It is better to have an understanding of what this emergency may feel like, then to be so horrified by it that they spit the regulator and bolt.

It sounds like the training agencies have added this back in after my course that is lovely. My bottom hours are well in excess of 800 (I can't be bothered going to check exactly). At this stage having completed enough dives I can not fathom me "just running OOA". My understanding of my gas consumption in many different situations is through. I know what I can or can not do on the fill I get in the tank I am using before I get in the water. When I get in the water if things are different than expected I manage my gas accordingly. I personally see no reason to expect this to change. Of course equipment failures can happen which is why we service, maintain and check our equipment carefully.
In the event that an emergency happens I am not likely to be so horrified I spit out my reg and bolt for the surface. Yes I recognize under the right set of circumstances anyone can panic but the best indicator of future behavior is relevant past behaviour. I have been in a number of life threatening situations and maintained control.

We teach that you are to keep your regulator in your mouth in this sort of emergency and that you can expect to get a little more air as you ascend due to the decreasing ambient pressure and the concomitant increase in pressure differential between the tank and the external pressure... yes?

So does it make sense to teach that you can get useful air volume when the ambient pressure changes by say 15 psi? Does 15 psi REALLY give you air to use? The instructors will teach that coming up 30 feet (+/- 15 psi) will yield some air to use.

Yup.. I know that and understand Boyle's law it was taught in OW basics.

So next time you are gonna get your tank filled, hook the regulator up, press the pure until the gauge says 100-50 psi, and then see how long it takes to drain the tank by breathing from it. See for yourself if you can gently press the purge button and slowly sip the remaining few psi from the tank...

Either, some other people are correct and it will breath perfectly normal until one last breathe - where air will just completely stop, or am I correct and you will be able to sip the last dribbles of air from the tank as you press the purge.. almost like breathing through a straw..

I did mention, that the ability to detect the decreasing pressure is a function of the regulator AND how hard you are initially sucking on the tank. With a very hard and fast inhalation, you should be able to feel some restriction in flow rate - of course this is more pronounced at depth.

The point I tried to make in my post was that all this testing sounds pretty kewl. It is one thing to do this while you are concentrating on your breathing and how the reg is delivering knowing you are safe and dry or the instructor is there with an alternate. It is quite another thing for the diver who is task loaded, concentrating on Navigating, take a pic or just fascinated by what they are seeing to even notice a change in how the reg delivers until it is pretty much the last breath anyway. IMHO Bob is right on the money teach gas management so it never happens. I am sure that any decent instructor stresses to their students during the air depletion exercise that the goal should still be to never get themselves into this situation in real life.

 

[dumpsterDiver]

The point is not that you are such a great diver that it will never happen to you.. maybe you feel the whole discussion is similar to what you are going to do if a flying saucer lands in your back yard...

Running out of air is a big problem in recreational scuba- just look at the accident reports..

 

[bowlofpetunias]

:lol: Missed my point did ya :doh: I'll make it really simple. Gas management is more important than breathing a tank dry and thinking you will be able to recognize the sensation early enough to save your life! The opinion of "Just an average diver"

 

[uncfnp]

:lol: Missed my point did ya :doh: I'll make it really simple. Gas management is more important than breathing a tank dry and thinking you will be able to recognize the sensation early enough to save your life! The opinion of "Just an average diver"

But the most beautiful part is that one does not negate the other!

One can learn and practice "gas management" but still learn the feel of a tank low on gas by intention.