Telling your dive buddies you may go Out of Air on this dive?

[Wookie]

I've been out of gas twice. Both times I was installing moorings, both times I had a redundant gas supply with me, both times I knew when I was running out, never was it a surprise. Meh.

 

[The Chairman]

I've been out of gas twice. Both times I was installing moorings, both times I had a redundant gas supply with me, both times I knew when I was running out, never was it a surprise. Meh.

So, you really didn't run out at all.

But people lose track of time when they're trying to tie one on.

 

[Wookie]

So, you really didn't run out at all.

My point exactly. 2 of our 3 fatalities involved someone out of air.

 

[2airishuman]

I would like to point out that some OOA incidents occur because of equipment failure. Survivor narratives on SB have included:

1) sudden full blockage of the tank valve by debris at depth
2) 1st stage seat delamination leading to a sudden full blockage of the 1st stage
3) numerous cases of mouthpiece detachment
4) 2nd stage breakage due to impact

An aware, experienced diver can recover from the last two by switching to a secondary. There isn't much to be done in the first two cases, other than prevention through maintenance, or another air supply.

 

[NAM001]

So we all do the training in class of what to do when we go Out of Air, but how many of you let your dive buddies know prior to dive, you may go out of air on this dive? I'm talking about doing the drill not actually going OA. I only do this with other seasoned divers with lots of dives, (not new divers). How many of you do this from time to time? What are your thoughts about doing this semi unplanned training drill?

I dont do unplanned drills
I may plan a drill and tell my buddy about it ............ but only because it is a dive item or skill profiency thing. And we both plan the event. When i initiate it i purge a reg to show i really have air then give the sign and see how things go. All this is prearranged prior to getting wet. We do all the drills. lost buddy lost fin mask ect. For my and the bud lost reg is a no drill item as we have our spare on a necklace.

 

[The Chairman]

I would like to point out that some OOA incidents occur because of equipment failure.

Let's take a look at these equipment failures:

1) sudden full blockage of the tank valve by debris at depth

Debris in the tank is not an equipment failure. This is human error.

2) 1st stage seat delamination leading to a sudden full blockage of the 1st stage

I would like to see the thread on this. I have seen the seats crack and cause a free flow, which you can almost always surface with. Hell, I've had that happen to at 80 ft. Not much of a safety stop, but it was safe.

3) numerous cases of mouthpiece detachment

That's a skill problem if you're OOA because of this. Learn to breath on a nekid reg or go to your safe second.

4) 2nd stage breakage due to impact

In the water? Again, I would like to see this. This is not a hard craptastrophe to negotiate. Breathe off the freeflow or switch to your safe second.

Almost all free flows can be mitigated by simply kinking the hose. This is not good for the hose, and I would be changing it when I got topside. But, it will control air flow so you don't run out. There are a few 'kink-proof' hoses out there, but I don't use them and I bet you could still kink them in a pinch.

Equipment failures happen but rarely. 99.999% of the time, it's diver induced and you should be able to negotiate a safe ascent without the need for your buddy's air.

 

[MaxBottomtime]

If a buddy came up to me and said he was OOA and I later found out it was just a drill he would no longer be my dive buddy. I expect my buddies to be able to check their own gear and watch their gas supply. The only times I have shared air with another diver was to extend the swim to our exit rather than make a surface swim.

 

[The Chairman]

The only times I have shared air with another diver was to extend the swim to our exit rather than make a surface swim.

Yeah, I've done that as well. I almost always dive a BAT (Big Ass Tank), so I have enough gas for anyone who needs it.

 

[2airishuman]

Debris in the tank is not an equipment failure. This is human error.

I'm not sure I see what sort of distinction you're trying to make. IIRC the story was that he got his tanks VIP'd every year and figured he maybe got a wet or contaminated fill on a boat at some point in the months preceding the accident. I myself have become very paranoid about my gas sources and am getting all my fills at the same shop, who share my paranoia, have a Rix, and are in a freestanding building with no other tenants. That isn't practical for everyone.

I would like to see the thread on this. I have seen the seats crack and cause a free flow, which you can almost always surface with. Hell, I've had that happen to at 80 ft. Not much of a safety stop, but it was safe.

This was the outcome for whoever it was who dove a Conshelf XIV for years and years with no service to see what would happen.

There have also been instances, usually involving recent service rather then neglected service, where the pin that lifts the HP seat has broken -- probably because some genius tech bent it and thought it would be a good idea to just bend it back.

Equipment failures happen but rarely. 99.999% of the time, it's diver induced and you should be able to negotiate a safe ascent without the need for your buddy's air.

I agree with the sentiment but not the percentage. We've both read the accident reports.

I would agree that maybe 80-90% of OOA emergencies are nothing more than failures to plan and manage the gas supply in a prudent fashion.

It is my conjecture that maybe 10-20% of OOA emergencies have some major contributing factor other than gas planning and management. These would include: gas turned off, navigation failures, poorly handled freeflows of various etiologies (purge button stuck, crud in reg holding diaphragm open, ice, whatever), mouthpiece loss, lost regulator, narcosis, etc. The exceptional situation where equipment failure causes a complete loss of gas flow without warning is rare but I believe it's about 0.1%-1% of OOA emergencies.

 

[The Chairman]

the story was that he got his tanks VIP'd every year and figured he maybe got a wet or contaminated fill on a boat at

Where was the dip tube? That's nothing but carelessness.

This was the outcome for whoever it was who dove a Conshelf XIV for years and years with no service to see what would happen.

No service? How is this not "neglect"? That's not an equipment issue, but abuse. I would also question the veracity of the story. Those HP seats aren't composites, where they can delaminate. If they cracked or popped loose of their mount, they would simply free flow.

There have also been instances, usually involving recent service rather then neglected service, where the pin that lifts the HP seat has broken -- probably because some genius tech bent it and thought it would be a good idea to just bend it back.

Again, this isn't an equipment issue, but rather gross incompetence. It's probably why I don't let others rebuild my regs. No one is more concerned about my welfare as I am. This summer marks 48 years of diving for me. I've had gear fail, like a distorted diaphragm on the last reg I let someone else touch. I've had o-rings pop, hoses blow, elbows come off, and more. Probably the only time I had an equipment failure that could not have been dealt with with a safe ascent, as when I was diving a prototype reg for @cerich and the first stage exploded. Fortunately, I was still on the beach when that happened since I was diving solo without a bail out bottle. I haven't made that mistake since.