Question Practicing Out Of Air ascent: good idea, or bad idea ?

[Roger Hobden]

Is it considered a bad idea, or a good one, to practice Out Of Air ascents (with a functioning regulator in mouth, of course), and if so, what is the SLOWEST realistic and SAFE rate of ascent for a diver that is not panicking (and who does not want to panic) ?

Say an OOA episode at 10 meters: a recommended rate of ascent in a normal situation would be to cover that distance in approximately 30 seconds. Can a diver safely exhale all the way up while traveling towards the surface at such a speed ?

Should people even try to do such an exercise, to acquire reflex muscle memory and be able to do this flawlessly if such an emergency occurs ?

Of course, you are ALWAYS supposed to be at touching distance of your buddy at ALL times, so I'm not debating this aspect, not at all.

 

[TMHeimer]

Is it considered a bad idea, or a good one, to practice Out Of Air ascents (with a functioning regulator in mouth, of course), and if so, what is the SLOWEST realistic and SAFE rate of ascent for a diver that is not panicking (and who does not want to panic) ?

Say an OOA episode at 10 meters: a recommended rate of ascent in a normal situation would be to cover that distance in approximately 30 seconds. Can a diver safely exhale all the way up while traveling towards the surface at such a speed ?

Should people even try to do such an exercise, to acquire reflex muscle memory and be able to do this flawlessly if such an emergency occurs ?

Of course, you are ALWAYS supposed to be at touching distance of your buddy at ALL times, so I'm not debating this aspect, not at all.

I practice this regularly. The CESA (Controlled Emergency Swimming Ascent--PADI). There are a few threads on this. IMO there is no reason to include it in the OW course unless you practice it later and know you can do it. Then again, many (instructors usually) feel it should not be in the course-- one reason being they must go up & down a lot with students on the same dive. I've ascended numerous times on dives of 20 - 30 feet (6-10 metres) with no problems. I usually do the speed you mention. Not sure I could do it twice as slow as the US Navy and some agencies recommend.

 

[Roger Hobden]

So the US Navy recommends to take 60 seconds to ascend to the surface from 10 meters ? That's 6 seconds per meter. It would require a lot of self-discipline for sure.
So from 30 meters, 3 minutes ? That sounds like an eternity.
Good to know that such a thing is doable, though ( in theory, at least ...).

 

[Marie13]

Is it considered a bad idea, or a good one, to practice Out Of Air ascents (with a functioning regulator in mouth, of course), and if so, what is the SLOWEST realistic and SAFE rate of ascent for a diver that is not panicking (and who does not want to panic) ?

Say an OOA episode at 10 meters: a recommended rate of ascent in a normal situation would be to cover that distance in approximately 30 seconds. Can a diver safely exhale all the way up while traveling towards the surface at such a speed ?

Should people even try to do such an exercise, to acquire reflex muscle memory and be able to do this flawlessly if such an emergency occurs ?

Of course, you are ALWAYS supposed to be at touching distance of your buddy at ALL times, so I'm not debating this aspect, not at all.

I think your time would be better spent learning how to dive plan so you don’t go OOA. Returning to the boat with 500psi is not good dive planning. Learn how to calculate your SAC/RMV, calculate how much gas you need for a dive, turn pressures, etc.

 

[inquis]

So from 30 meters, 3 minutes ? That sounds like an eternity.

Deeper dives may warrant redundant air, sidestepping the whole CESA issue. This is part of @Marie13 's suggestion.

 

[Roger Hobden]

I think your time would be better spent learning how to dive plan so you don’t go OOA. Returning to the boat with 500psi is not good dive planning. Learn how to calculate your SAC/RMV, calculate how much gas you need for a dive, turn pressures, etc.

Well, naturally, I know that.

My question wasn't about the whole gas management issue, but only about practicing OOA ascent.

Do you have any advice you would want to recommend about that specific question ?

 

[Marie13]

Well, naturally, I know that.

My question wasn't about the whole gas management issue, but only about practicing OOA ascent.

Do you have any advice you would want to recommend about that specific question ?

Think it’s a waste of time. Repeatedly doing it in the same dive is a good way to jack up your ears, besides whatever else you could do to yourself even doing it once.

Going OOA is a Very Bad Thing. You shouldn’t prepare for it to happen. I’m cave trained. Running out of breathing gas in a cave means you’ve effed up in a major way. That mentality seems to be lacking among some recreational divers.

 

[Roger Hobden]

Going OOA is a Very Bad Thing. You shouldn’t prepare for it to happen. (...) That mentality seems to be lacking among some recreational divers.

Well, if some agencies, like PADI for instance, teach about the OOA issue in this way of thinking to recreational divers, then obviously the "example", if you will, comes from much higher up than the individual diver him/herself ...

 

[Marie13]

Well, if some agencies, like PADI for instance, teach about the OOA issue in this way of thinking to recreational divers, then obviously the "example", if you will, comes from much higher up than the individual diver him/herself ...

PADI apparently teaches to the lowest common denominator. Be a smarter diver and go beyond that. What’s your diving? Are you an independent local diver or are you a holiday/vacation diver following a DM? Even if you’re the latter, no reason to act like one of the herd.

 

[PatW]

I have about 1000 dives. I recently had my primary regulator free flow. It was late in the dive at 40’ and I has something like 1500 psi. So I thought no big deal, the dive master was at the safety stop, so I showed my buddies the situation and went up to do a safety stop. I could have made the surface easily, but not the surface stop (Which surprised me). But the dive master shared. I had the reg serviced recently and a little piece of loose plastic was the issue. And I had about eight dives on it before it free flowed and adjusting it did not help.

And a buddy of mine has a hose go on a dive with similar results. He had plenty of air at the time and would have made it to the surface but making the safety stop maybe not.

A catastrophic equipment failure is pretty rare and I have seen two and neither would have necessitated a CESA. Also, the equipment in both cases was regularly seviced. You should be near enough to your buddy to get assistance in that circumstance.