Ooa

[DiverBuoy]

It hasn't happened but I will never say never. Along those lines I have for some time been under the assumption that my SAC was still .6 - I hadn't calculated it in a while. But recently I did a recheck on my last 50 dives - my lifetime SAC averaged is now around .5 with many recent dives between .39 - .45 so I can often get 2 hour dives out of a single tank. I've never dove with a buddy yet who has better air consumption so they always become the bottle neck, the signalling on any dive. Forget students ever coming close, or me forgetting to check regularly or push the limits. All things considered - it would take a lot to reach OOA for me.

However, I will be the first to say "NEVER say never". Plan for contengencies, equip for contingencies, buddy dive, and practice OOA emergencies - all these things help - but it could STILL happen.

 

[Popeye]

ebbtide once bubbled...
I wish i could say it has never happened to me but it has .
i was at 50 ft and picking sea urchins knowing that i was below 400 psi i contuned to work

The closest I ever came to OOA...

Several years ago I was at the tail end of a 90' dive, 750psi, and I found an anchor, brand new looking, and it was pretty big. I shoved it in the cummberbun of my BC, and headed up. I had like 650psi, no problem. I go up to about 50 ft, the anchor rope is hung in the rocks.

The first 10-15 feet of line is chain, so I reel it in (going back down) and cut it. 300psi.

Now I can't drop the anchor, because because there's divers below me...

Safety stop.... 200 psi...

Not really too concerned, there's other divers around me.

I make it up on my own, the SPG at zero.

Quite the learning experience. It goes to show how a simple task can turn complicated quick. I knew exactly what my air was, but couldn't drop the anchor for fear of whacking someone below.

Funny thing is, I don't even own a boat. I gave the anchor to the charter captain.

 

[Uncle Pug]

Popeye once bubbled...
Funny thing is, I don't even own a boat. I gave the anchor to the charter captain.

...you could have taken the bitter end of the rope up instead and pulled the anchor up later... or better yet... using line from your spool sent the bitter end up with your dive marker.

 

[raybo]

but didn't think about the case of jumping in with the air turned off. Leaky rented tank o-ring ( I'm sure no one has ever had that!), turned off after setting up, long lazy boat ride soaking up the sun. I'm hot, ready to get in the water. Quick hit on the power inflator, half a draw on the 2nd stage. I heard the inflator and drew a breath! Look at the SPG~ 2950 ~ I'm good.) Everyting s OK. Hit the water, one good draw and its's over.

Turned out the valve itself was a llittle worn out as well, and it leaked enough to keep the line pressurized, but not enough to breathe on.

Glad one of the things I was trained was how to do that task on you own, in you gear, in the water. It was quicker than getting to anyone else.

For the most part, try to do what they teach you, at 1000, look to be getting out, 500 on the surface. Lowest I can remember was 200 from waiting on a line in surge . Guess I'm just conservative

Diverbuoy once bubbled...

Along those lines I have for some time been under the assumption that my SAC was still .6 - I hadn't calculated it in a while. But recently I did a recheck on my last 50 dives - my lifetime SAC averaged is now around .5 with many recent dives between .39 - .45

<big sigh> I remember those days...then I got my drysuit, and that went out the window. Oh, well, if I ever get the darn thng figured out, I 'm sure it'll get better again.

 

[Wreck Ranger]

It has only happened once to me. I was diving with a new buddy and it was when I first got into diving. We were on a wreck in N.C. and on the way back to the anchor line the current picked up to where you almost couldn't swim against it. I kept trying to keep up with him but he was going too fast and wasn't looking back. I finally made it to him and signaled that I had 500psi left and was going to out soon since we were at 90' and hadn't started our descent. At that point he finally realized what I was signaling to him and we were close enough to the anchor line to see it, so we started our free ascent. When we reached the hang for our safety stop I was out of air and there was someone on the emergency air hose hanging off the side of the boat. We buddy breathed until to person on the emergency regulator left it and surfaced.

When we got on the boat he told me that he wasn't paying attention to me and he was sorry. My father wasn't happy with either of us and I sat out the last dive. It was a good learning experience for me and it has never happened since then. I have never dove with that guy again. Its interesting how your body reacts to things under the water. When I realized that I was about out of air a quick rush of adreaneline but right after that I felt pretty calm and did what I was supposed to do from my training. It was an eye opener and I took diving in a whole new light.

What I should have done is when my buddy didn't respond to what was happening to me I should have started my ascent right then and would have been back on board with air still in my tank.

Hopefully these stories will help someone realize how important it is to watch your gauges and study your training manuals and always refresh yourself every chance they get

Nathan

 

[Popeye]

Uncle Pug once bubbled...

...you could have taken the bitter end of the rope up instead and pulled the anchor up later... or better yet... using line from your spool sent the bitter end up with your dive marker.

Ahhhhhhh, the things I know now.

Of course you're right.

The hindsight of experience.

The "bitter end" (never heard that before) was elsewhere (at least 90 ft long), the anchor was at hand, and my dive marker was a collapsible flag.

I don't think it has the lift...

I carry a Spool now, with a heavier line, and a DSMB.

In case I find another anchor...

 

[nickjb]

Popeye once bubbled...


The closest I ever came to OOA...

Several years ago I was at the tail end of a 90' dive, 750psi, and I found an anchor, brand new looking, and it was pretty big. I shoved it in the cummberbun of my BC, and headed up. I had like 650psi, no problem. ......

I'm not really in a strong position to comment having come close to line a few times but in Europe we aim to be back on the boat with 50 bar (725 psi)

 

[Popeye]

nickjb once bubbled...



I'm not really in a strong position to comment having come close to line a few times but in Europe we aim to be back on the boat with 50 bar (725 psi)

I would never criticize that, if it's your comfort margin.

Each diver should do what training, experience and -comfort- dictates.

I suspect that if you checked SPGs of returning divers, you'd find an average that's a bit lower...

Since charter boat diving all boils down to buying bottom time minutes for dollars, I like to get my money's worth.

Same reason I dive Nitrox, and a computer.

On my average 80-90 ft dive, I leave the bottom at 700psi.

I usually hit the boat with 200.

I don't want to waste around 20% of my gas.

 

[raybo]

Popeye once bubble...

I suspect that if you checked SPGs of returning divers, you'd find an average that's a bit lower...

Since charter boat diving all boils down to buying bottom time minutes for dollars, I like to get my money's worth.

...I don't want to waste around 20% of my gas.

I've been on some cattle boats where everybody dives as a "group", and even after running cleanup and lagging behind everybody, be the last one back on the boat with 1000-1200, and everybody else is, as UP put it, trying to create a vaccuum in their tank, and still lots of NDL left because it wasn't that deep.

That's a drag!

 

[Bob3]

Back before the advent of SPGs, the pull rod or J-valve handle would get whacked, turning on your "reserve". We'd remove the pull rod making the unintended activation less likely to happen, just reach back & turn the lever down.
The handle would still get whacked sometimes tho, making a bailout bottle a good thing to have in an overhead situation.
Hookah compressor runs out of gas, time to come up while sipping the leftovers in the hose.
Had my air hose chopped once while hardhatting, used to freeze up sometimes too if we forgot to dump some Everclear in the volume tank.
Overall I'd rate an OOA an annoyance rather than a problem.

Folks that said "never happen" should rethink that answer, always plan & practice.