OOA and Situational Awareness...

[TSandM]

I think we're getting a little sidetracked. The two biggest lessons from this dive, in my view, are a) that one should not get distracted and run out of gas, and b) that everyone on the dive should retain a sufficient gas reserve so that, if someone has to be brought up on someone else's gas, it isn't a race against time to get to the surface before the supply is exhausted. This CAN be done! We don't turn out OW divers with the tools to do it, unfortunately, but the information is out there, as Bob shows in the link in his early post.

If gas reserves have been maintained, the choice of doing a safety stop or not can be based on the emotional state of the OOA diver, rather than available air.

 

[2 Big 2 Fail]

I'm very new to diving, so I still think of a lot of things in terms of the other critical missions kind of activities that I've spent most of my life in. I would not be surprised, if I was seeing this scenario being controlled by a diver in full and calm possession of his faculties but dealing with an emergency, of seeing a safety stop. We strongly tend to revert to training under stress, and the training we revert to is the simplest version. The simple version seems to me to be: We're ascending, and we're breathing, therefore there's a safety stop. While that's not a true statement in all cases, it's still the simple impulse.

Obviously, if you look at a gauge and see what makes you expect to start sucking vacuum momentarily, a safety stop is no quite the best decision. But aside from the training reflex, there's considerable comfort in the feeling that you're following training. If it's not clearly contraindicated, I can't fault someone for a safety stop that helps keep things cool by suggesting that "we had a problem, but it's really not so bad now if we can still do our safety stop." Are there more things that can go wrong during the stop? Sure, just as they can on the surface. But the point is that the safety stop in this case isn't surprising and probably represents a training effect that isn't such a bad thing.

In some situations, the "safety stop" might be of unlikely physiological benefit but might be just the right pause before dealing with the surface, and there's probably something that could be said that's analogous to the pilots' "A good landing is one you walk away from."

I wonder that new divers aren't required to read and analyze a ton documented accidents. There are so many things to drill on in training that it's easy to miss the emphasis on the reason for most of the drills. And that's that if you ask, "What kills divers?", its the same answer as, "What kills pilots?" Lack of air. Someone talked about, years ago, essentially every dive ending out of air. That's worth thinking about. We don't think that way today, because we have a gauge. Therefore, having a gauge, we don't expect to run out of air, but we do, when we don't keep up with the gauge, and I suspect the psychological shock is more severe now.

 

[DevonDiver]

I think we're getting a little sidetracked.

I read the thread title a little differently The point I would make is that being OOA (or any emergency) is not the time to lose situational awareness. In respect of safey stops, that awareness would mean:

"Do we have enough air to complete a stop?"

"Has my ascent been fast or erratic, thus increasing the importance of conducting a stop?"

etc etc etc

 

[TSandM]

Good point, DD. I read the title as referring to the failure of SA that led to one diver out of gas, and the other low on it. But SA doesn't end when you recognize an emergency -- in fact, maintaining your ability to acquire and process information DURING an emergency and the procedure to manage it, is equally critical.

 

[NAUIwowee]

What evidence do you have that this is true? I dive everything from a jacket style to no BC at all and just about everything in between. There is little difference in my SAC reguardless of the BC I am wearing. Preference is one thing, I have my own preference. SAC is a function of diver skill and is for the most part non-equipment dependent or at least not BC or reg dependent.

I'm with Herman on this. I don't understand the reasoning behind this statement. I have always used a jacket style BC. As a DM, I'm usually the first one in the water and the last one up the anchor line and I almost always have more air left in my tank than anyone else when we get back on the boat. Even when I'm diving with others who are using back inflation. I've never had a desire to switch to back inflation, but if it's going to somehow increase my SAC rate then maybe I'll consider it.

 

[DevonDiver]

Ignore the SAC rate issue. The only way that switching to a back-inflate/BP&W system would improve your SAC is due to decreased water resistance through improved streamlining and trim.

It's also off-topic

 

[fxrguy]

What evidence do you have that this is true? I dive everything from a jacket style to no BC at all and just about everything in between. There is little difference in my SAC reguardless of the BC I am wearing. Preference is one thing, I have my own preference. SAC is a function of diver skill and is for the most part non-equipment dependent or at least not BC or reg dependent.

The only evidence I have is that in 30 years of diving I almost never see people wearing jackets come close to the consumption rate of wing divers. Nothing scientific mind you but I'm just saying... If it looks like a duck it's probably a duck! The only times I've seen anything close is when jacket divers know they are being challenged and adjust their breathing accordingly. Really didn't want this to turn into a jacket vs wing controversy but I guess some things never change.

 

[fxrguy]

Thank you... That's was the point of the post in the first place. Nobody plans an accident but as ready as we think we are sometimes accidents happen anyway. Distractions happen and most of us are just mere humans. **** happens! Didn't mean to step on anybody's toes about who's BC is best or who can piss the furthest.

 

[fxrguy]

In he future I will be careful when making a post to not imply that anybody who is so "together" in their diving skills could ever have a situation similar to this happen to them, or make any intentional or non-intentional references about their diving gear so as to hopefully try staying on the subject! Heck I should have just told you about my last trip to Disney World.

 

[fxrguy]

I think we're getting a little sidetracked. The two biggest lessons from this dive, in my view, are a) that one should not get distracted and run out of gas, and b) that everyone on the dive should retain a sufficient gas reserve so that, if someone has to be brought up on someone else's gas, it isn't a race against time to get to the surface before the supply is exhausted. This CAN be done! We don't turn out OW divers with the tools to do it, unfortunately, but the information is out there, as Bob shows in the link in his early post.

If gas reserves have been maintained, the choice of doing a safety stop or not can be based on the emotional state of the OOA diver, rather than available air.

Thank you... That's was the point of the post in the first place. Nobody plans an accident but as ready as we think we are sometimes accidents happen anyway. Distractions happen and most of us are just mere humans. **** happens! Didn't mean to step on anybody's toes about who's BC is best or who can piss the furthest.

In referance to TSandM's post...