Have you ever run out of gas, or been close?

[currier]

I've been OOA once ... during an unnecessary safety stop at the end of a dive that had a max depth of ~18m. This wasn't long after certification, and we were diving the shore site where we trained ... The entry /exit is a piece of cake, I was within arms reach of my buddy, and my instructor wasn't far either ...

So I just popped up from 4m-5m.

I've closely monitored my air and run it down to 20 bar on a few occassions ... this is something I shouldn't have ever done since SPGs can give false readings ...

 

[freewillie]

Lowest I've been on gas just under 500 psi but had planned dive include safety stop for that day. I've yet to dive deeper than 60 feet however, and haven't really done anything more challenging than beach dive with moderate surf.

 

[Crush]

In Oct 2008 I was a newly-minted diver who had about 20 dives under his belt and had been certified five months earlier. I believe that I had not yet completed my AOW training. I am land-locked, so most of my dives had been in fresh water, that is, dull and gray. I check my gauges religiously - you would think that I would be the last person to get near-OOA. However, in Oct 2008 I jumped into the water off Quadra Island in British Columbia. I had never seen such colour and I spent the dive giggling like a little girl. Oh sure - I checked my gauges a few times, but I was very distracted by the invertebrate life, plus I was getting used to the current a bit (which was actually fun). At one point my dive buddy (who knew that I was new) motioned for me to check my gauges. I found to my surprise that I was down to 300 psi (in one Al 80) at 70 fsw. We had previously agreed that since I was a hoover I would surface on my own. I signaled my intent to surface and made a controlled ascent at about 60 fpm to thirty feet (consistent with my training), then at 30 fpm to twenty feet where I held on to some kelp and did a full three minute safety. As it happens, every inhalation at 20 feet dropped my tank pressure by about 5 psi. When my full three minutes were up I ascended slowly to the surface and ended up with a huge 50 psi (about ten breaths) in reserve.

...

Postscript: According to my basic-OW licensing agency (ACUC) my depth restrictions were 80 feet for the first 20 dives or 10 hours accumulated dive time, then 130 feet after that point.

 

[elmer fudd]

I probably do 2/3 of my dives using vintage gear, which occasionally means no SPG. On those dives I use a J-valve, so I've been low enough a few times to pull that reserve lever, but never entirely out of air.

My experiences with J-valves aren't that you suddenly run out of air, but that at some point you notice, "hey, it seems like I'm working pretty hard to inhale", then you pull the lever and everything goes back to normal.

 

[Quero]

I've never accidentally gone completely OOA, but I did come close once. It was at Nusa Penida's Blue Corner during the mola-mola concentration season. We had spent the entire dive swimming along a wall looking for the creatures without success, and most in the group were getting low on air, so the DM signaled a safety stop on the reef flat. But of course just at that exact moment, the molas came into view--five of them just lined up nearly catatonic with the banner fish doing the fish-spa thing all around them--just PERFECT for photography. I did a quick calculation using my RMV, estimated the depth, checked my remaining gas and decided that I had plenty of air (80 bar) to go down to where they were to get a couple of shots, so I signaled my intent to the DM and took off. As soon as I reached depth, though, I realized I was going to violate my NDL, so I changed my mind and headed back to the wall to go up, hoping the molas would hang around and I'd catch them on the next dive. Unfortunately, the outgoing tide had just picked up and was washing over the whole extent of the reef edge like a huge Niagara, and I couldn't simply surface! I was alone, fighting a wicked down current to climb the wall, but I just had to do it since if I didn't surface right there, I'd miss joining the group for the boat pickup. I blew through nearly all of that gas going up the wall about 20 meters and got to the top with maybe 10 bar. I signaled low on air as soon as the DM caught sight of me, and he came to offer his octo for my safety stop. That was the closest I have ever come, and I was concerned, making plans for a CESA if I needed to, and I certainly could have, but I was glad to be able to do the stop after having worked so hard on that ascent. Mistakes? I shouldn't have decided to do a solo descent at the end of the dive; I should have asked about the tide table when I was planning the dive.

 

[TheCanuck]

Never ran out of air and don't remember being real close either. I have seen a guy coming damn close to emptying his tank however. It was this January in Roatan. This guy ran his cylinder down to 200psi but signaled the DM he was at half tank. I handed him my octo, called the dive and we surfaced together.

 

[Searcaigh]

I have been down to 30 bar on a few occasions where the dive has been so good on a fringing reef and I continued to take photographs in 3M depths.

Never experienced an OOA though.

 

[thkhoo]

Never OOA but a dodgy moment sticks in my mind:

Was diving in Sipadan when the wall gave way to a sandy slope which formed a sort of channel where we encountered a strong current going down and out to sea. Me and my buddy grabbed on to the sandy bottom but two other divers just kept finning and finning against the current, ignoring our signals to "get down and grab on". We were already towards the end of the 1hr dive at this point and I could see they were breathing pretty hard. So I signalled my buddy for us to let go of the sandy bottom and help these two other divers out.

We reach them and I grab hold of the closest diver and give him a good shake to get his senses back. I grab his SPG and he's on 30bar! I had about 70bar. I signal for him to STOP FINNING and that we would be ascending. To stop him panicking after seeing his own air supply, I shove my octo into his mouth and guide him up to 5m where we do a 3min safety stop. All this time, I'm looking at my gauge declining rather rapidly as he's still breathing hard. By the time we surface, 5 mins after my buddy and I let go of the bottom, I'm down to 25bar and we're more than half a kilometre away from any of the boats.

I chuckle to myself at this point because just that very morning, these two divers (and my buddy too actually!) were giving me a hard time for carrying around a safety sausage when the "visibility is so amazing" that "we'll NEVER need it". Well... guess who was grateful that I had carried my safety sausage after all!

 

[packeteer]

If your question is have I ever unintentionally been out of gas, the answer is no. I've intentionally ran my tanks either very low, to almost completely empty on several occasions.

same. I was in about 2m of water and ran the tank down to 10bar on purpose

 

[herman]

I agree with everything said here, except I'd add that the deeper you are the quicker things happen. Just because you feel comfortable "sucking" 8 or so breaths at 100 psi in 10 foot deep water, does not mean you will be able to "suck" a whole breath at 50 feet.

While the total number of breaths at 50 ft will be less, the same ever increasing breathing resistance will still happen, its not going to be 2 or 3 breaths and nothing. You still have to drain the tank from roughtly 150 psi above ambient (reg IP) to nearly zero above ambient before the is no more air and the regs totally stops, the last few breaths are going to be really hard to suck from the tank but they are there. The good news is as soon as you start to accend you start to get more, easier to get gas available to you as the ambient pressure around you decreases. The main point remains, your reg will tell you that you are getting very low on gas for a some amount of time before there is nothing. I am in no way suggesting this is a good idea in deep water (a great exercise in shallow, very controlled conditions IMO) but rather that while there is no time to waste or do a safety stop, there is time to surface if you get moving assuming you were paying attention to what your gear is telling you........but then again, if you were, you would not be that low in gas to start with.