Out of air emergencies

[captain]

There's a pretty good thread going on talking about how to with with an OOA situation. Can you rely on your buddy, should you carry a pony, etc. I've got a question about the root cause of the problem.

Is there anything that can cause OOA other than sucking it down too fast and/or not paying attention to your SPG? Seems to me that any diver can pretty easily avoid this situation by paying attention to what they are doing. What am I missing?

Nothing.

 

[Guba]

My one and only OOA experience was on a dive along the Rivera Maya and was caused by debris in the tank provided by a local dive charter. Corrosion in the tank made its way into my first stage after I inverted to photograph a turtle (yes, it made it past the tank "snorkel"), and SEVERELY limited the amount of gas I was able to get, perhaps about 10-20 percent. Other than being very careful about whom one books a dive, I am at a total loss as to how to prevent an incident such as this. It happened when I still had about 1600 psi, my regs and other personal gear were in top condition, and I was totally aware of my surroundings, guages, and situation...right up to the moment I tried to draw a breath and met almost total resistance. While this type of OOA situation has to be about the rarest, it emphasizes why it's a good idea to practice drills covering this type of thing on a regular basis.

 

[fyrdyvr]

The instructor that taught my OW class told me that he was ascending to the boat on a dive and a huge school of jellyfish (not sure if a group of jellyfish are called schools or not) was directly overhead and he couldn't surface until they passed. He told me that when he surface that he had less than 100 psi, and was really worried.

I guess if anything the story made me realize that despite the best planning, ANYTHING can happen, and you must be mentally and physically prepared to stop, think, take control and act!

 

[IceIce]

Incident 3 (not really OOA, but we had to share air anyway):

I was diving with three recently authorized research divers at a location where there is a large permanent gill net that all divers had been instructed to stay well clear of. We were diving as two separate buddy pairs. My buddy and I had completed our dive and were returning to shore on the surface when one member of the other team surfaced alone, near the net. I asked him were his buddy was and he said he did not know, that was why he surfaced. I looked around for bubbles and saw some coming up not far away. I told my buddy and the other diver to follow me and dove down on the bubbles. I found the "missing" diver tangled in the net, struggling to get free. She had gotten into the net as she surfaced since the current had bowed the top of the net over her. She had first taken out her knife to cut herself free but had dropped it, and it was now out of reach on the bottom. She had then tried to take off her tank and had somehow managed to wind her intermediate pressure hose around her neck and was now badly fouled in the net. I signaled the two divers with me to buddy-up and stay clear. I approached the fouled diver, got her attention, and had her shift from her regulator to my octopus. I helped her to complete the removal of her tank and we surfaced together, leaving her tank in the net. After settling her down, my buddy and I submerged and recovered her tank from the net and her knife from the bottom.

You saved her life.

 

[Thalassamania]

You saved her life.

I don't think so, she'd have worked it out, eventually. She became one of our better instructors a couple of years later.

 

[gcbryan]

The only thing that's not mentioned enough is that even though OOA is caused by poor planning in the majority of cases it's the minority that matters since being underwater is an unforgiving place.

Who cares if OOA is usually preventable. No one is arguing that a pony bottle be used so that you can have poor gas planning skills. What about the rare situation where equipment failure/entanglement is occurring.

To argue for a pony is not to argue against good buddy skills and gas planning skills.

 

[Thalassamania]

The only thing that's not mentioned enough is that even though OOA is caused by poor planning in the majority of cases it's the minority that matters since being underwater is an unforgiving place.

Who cares if OOA is usually preventable. No one is arguing that a pony bottle be used so that you can have poor gas planning skills. What about the rare situation where equipment failure/entanglement is occurring.

To argue for a pony is not to argue against good buddy skills and gas planning skills.

I agree, it is a separate discussion and need to be looked at on its own merits and drawbacks.