IMHO certainly sounds like a combination of poor judgement and narcosis with a panic attack thrown in. I don't know any scuba related problem that "fixes itself" by going deeper. From what I read, the problem started at a shallower depth - The solution would have been to stop, assess the situation and ascend, not to dive deeper.
Regulator malfunction or just a normal occurance at 130ft?
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I agree the most likely suspects are narcosis and a partially opened tank valve.
Despite the depth, I suspect the latter as a slight decrease in depth, (10 ft or so) will often have a pronounced effect in terms of improving narcosis. A partially opened tank valve on the other hand gets progressively harder to breathe from in direct proportion to the depth and gas consumption rate.
To be fair, you do not notice a partially closed valve on the way down as easily as you would suspect as it creeps up on you, but the shortage in delivery becomes painfully obvious with the first rapid intake of air you attempt in order to over come the "I'm not getting enough air feeling" and when you don't get any more air, the anxiety level can spike unless you are working the problem logically.
In the extreme, a very low performance reg can have air delivery issues at depths of 100'-130' - but only under very high workload conditions - not just a normal swim. That said, once you start the semi-panic gasping for air, the immediate demand of each breathe could outstrip the ability of the reg to deliver it in the short time you are giving it. In contrast the same reg, just like a partially closed tank valve, could give you all the gas you want on an inhalation lasting twice as long. So, as someone suggested above, the solution is often to just stop, exhale slowly and completely to vent CO2 and then inhale slowly and assess the problem. As long as you are getting some gas, the problem is not immediate and you have time to think before you act.
I have to say after 25 years of diving and substantial over head environment training, it never even occurs to me to bolt for the surface (although I never had that urge even after only the first few months of diving) It just is not an option until I have totally exahusted every other option. If that feeling that you need to bolt ever occurs it is a clear indication that you lack the training and experience to be where ever you are currently at - even if it is only 30 ft deep in a quarry.
Personally I do not let anyone mess with my tank valve(s) on the boat, and expecially when I am getting ready to jump in. I have had crew turn my valves off (confusion over doubles and lefty- loosey, righty tighty) and if I feel anyone "steady" me, I'll recheck the regs while watching the SPG to make sure they are still on before jumping off.
Being able to reach your tank valve is a plus, even if you have to loosen the waist strap to do it, as having a buddy "open" it will result in the buddy fully closing it 50% of the time. Unless you are already on his or her octo, don't let them touch it.
In the past, it was common to open a valve and then turn it back a quarter turn to keep it from getting stuck. That is still often taught but there is no reason to do that with modern valve. Open them all the way to the stop and leave them. It will avoid many of the partially closed valve issues and reduces confusion -if you are getting air, the valve is fully open, as opposed to the valve being a quarter turn open and supplying enough gas at the surface but not at depth.
As pointed out previously, the best way to tell if it is a reg issue or a valve issue is to note the SPG. If the needle drops when you inhale, the valve is not fully open and you then know what is required - fully open the tank valve. If the needle is stable, it is a reg issue and you know you have to take another course of action - switch to the octo and if the problem is no better, share gas with a buddy and/or start a controlled ascent.
Despite the depth, I suspect the latter as a slight decrease in depth, (10 ft or so) will often have a pronounced effect in terms of improving narcosis. A partially opened tank valve on the other hand gets progressively harder to breathe from in direct proportion to the depth and gas consumption rate.
To be fair, you do not notice a partially closed valve on the way down as easily as you would suspect as it creeps up on you, but the shortage in delivery becomes painfully obvious with the first rapid intake of air you attempt in order to over come the "I'm not getting enough air feeling" and when you don't get any more air, the anxiety level can spike unless you are working the problem logically.
In the extreme, a very low performance reg can have air delivery issues at depths of 100'-130' - but only under very high workload conditions - not just a normal swim. That said, once you start the semi-panic gasping for air, the immediate demand of each breathe could outstrip the ability of the reg to deliver it in the short time you are giving it. In contrast the same reg, just like a partially closed tank valve, could give you all the gas you want on an inhalation lasting twice as long. So, as someone suggested above, the solution is often to just stop, exhale slowly and completely to vent CO2 and then inhale slowly and assess the problem. As long as you are getting some gas, the problem is not immediate and you have time to think before you act.
I have to say after 25 years of diving and substantial over head environment training, it never even occurs to me to bolt for the surface (although I never had that urge even after only the first few months of diving) It just is not an option until I have totally exahusted every other option. If that feeling that you need to bolt ever occurs it is a clear indication that you lack the training and experience to be where ever you are currently at - even if it is only 30 ft deep in a quarry.
Personally I do not let anyone mess with my tank valve(s) on the boat, and expecially when I am getting ready to jump in. I have had crew turn my valves off (confusion over doubles and lefty- loosey, righty tighty) and if I feel anyone "steady" me, I'll recheck the regs while watching the SPG to make sure they are still on before jumping off.
Being able to reach your tank valve is a plus, even if you have to loosen the waist strap to do it, as having a buddy "open" it will result in the buddy fully closing it 50% of the time. Unless you are already on his or her octo, don't let them touch it.
In the past, it was common to open a valve and then turn it back a quarter turn to keep it from getting stuck. That is still often taught but there is no reason to do that with modern valve. Open them all the way to the stop and leave them. It will avoid many of the partially closed valve issues and reduces confusion -if you are getting air, the valve is fully open, as opposed to the valve being a quarter turn open and supplying enough gas at the surface but not at depth.
As pointed out previously, the best way to tell if it is a reg issue or a valve issue is to note the SPG. If the needle drops when you inhale, the valve is not fully open and you then know what is required - fully open the tank valve. If the needle is stable, it is a reg issue and you know you have to take another course of action - switch to the octo and if the problem is no better, share gas with a buddy and/or start a controlled ascent.
Wow, and both are "AOW" and yet another example of why watered down scuba instruction does no favors to anybody.
Guess what, they are not only not "AOW" but they are not even beginners, they better hire another instructor and take Basic Scuba over again.
Yes, things fail, masks flood, deal with it, thus the purpose of the instruction they and possibly you never got. Sorry.
N
I am not willing to write off the reg being the cause just yet. I have a couple of old Sherwood Bruts, and once you go below about 90 feet, the air gets pretty sticky. By 150 feet it is like breathing glue.
This incident took place a few years back, who knows how old the rental gear was (and Sherwood Bruts certainly used to be a popular rental model because they were so tough).
Wasn't there, so I don't know - but I wouldn't write the possibility off.
This incident took place a few years back, who knows how old the rental gear was (and Sherwood Bruts certainly used to be a popular rental model because they were so tough).
Wasn't there, so I don't know - but I wouldn't write the possibility off.
halocline
Contributor
Maybe the regs weren't the best in the world, but it sounds like narcosis and anxiety to me.
I've been to 130 ft with a MK2/R190, not considered a high performance reg, it's even (gasp) unbalanced, the design hasn't changed in 20 years at least, and it performed just fine. People forget that a few decades ago pro divers were making extreme dives on regulators that most recreational divers today wouldn't take in the pool. I wonder how they got through it? Maybe those old regs aren't so bad after all.
Maybe the tank valve wasn't open all the way, but the description totally sounds like regular garden variety narcosis and the all-too-common circumstance of divers far exceeding their training on a charter. Not to point a finger at Belize, but a good friend of mine went there for a dive trip shortly after certification and end up at 80 ft on the first dive finishing the dive breathing off the DM's octo after a near panic and blowing through her air.
I've been to 130 ft with a MK2/R190, not considered a high performance reg, it's even (gasp) unbalanced, the design hasn't changed in 20 years at least, and it performed just fine. People forget that a few decades ago pro divers were making extreme dives on regulators that most recreational divers today wouldn't take in the pool. I wonder how they got through it? Maybe those old regs aren't so bad after all.
Maybe the tank valve wasn't open all the way, but the description totally sounds like regular garden variety narcosis and the all-too-common circumstance of divers far exceeding their training on a charter. Not to point a finger at Belize, but a good friend of mine went there for a dive trip shortly after certification and end up at 80 ft on the first dive finishing the dive breathing off the DM's octo after a near panic and blowing through her air.
I've had a Zeagle flat head that was incorrectly adjusted by a service tech that did that... you could breath off it ok on the surface, but at deeper than 100 ft, it was nasty.
And most octo's are usually adjusted to perform that way intensionally.
Later tests showed it was set just over 2 J/L at the surface...which put it at around 4 j/L at say 105 ft. That is more energy than a normal person (including me) can overcome without having breathing issues.
I switched to another flathead, on the next dive, and what a huge difference.
It is always possible that it is just the person, but unless I know the make, and it's test results, my first bet would be on the regulator.
Extreme-Dive-Justin
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This seems a bit odd, but a few factors may be the culprit. first of all, what type of first stage was she using? this can make a serious difference at depth. was it balanced or unbalanced. An unbalanced first stage is not really the best for deep dives as they do not produce a constant IP in low pressure hoses to the regs and the inflator hose. Whether it was a piston or diaphragm first stage does not matter, but for dives in excess of 30m/100ft I would suggest a balalnced first stage. These two types are usually reflected in price when buying a reg, but always ask.
Yes narcosis could be an atributing factor, or even if her air was only cracked on the bottle, depth can play a significant factor on the recharghing of intermediate pressure in her regs.
Only some suggestions.
rebreathe
It does not matter if the reg is balanced or not when we are discussing breathing characteristic changes due to depth. Balancing only comes into play with changing tank pressure and has nothing to do with depth. All scuba regs, regardless of design, are depth compensated. Even so, most divers cannot tell the difference in a few psi of IP change that is common on modern regs.
dougchartier
Contributor
Not that I'm an expert, but it sounds like nitrogen narcosis to me. My wife suffered from a bad episode of narcosis at the Blue Hole at 130' and, among other things, felt like her regulator wasn't giving her enough air.
On the same dive at 130', I felt like my regulator was giving me plenty of air and didn't feel any panic, but I could swear that the sound of the air coming out of my regulator was a little different (like it was a noticeably louder). At the time, I figured that it was because my regulator was delivering higher pressure air. Does the regulator sound different at greater depths? Or was this an effect of nitrogen narcosis?
The reg probably won't sound any different - the pressure inside the Intermediate pressure spaces is a little higher (about 65 psi higher at 130 ft than at the surface) but not enough to make any real difference in the sound.
I noted when I used to fly single engine IFR or fly over water in a single engine aircraft that the engine sounded different and I heard every little difference or change in the pitch and the sounds it made. That phenomenon is generally recognized as "auto rough" and is directly proportional to a pilot's reliance on the engine in a given situation.
I suspect the same thing is happening to you at 130 ft where you are focusing much more on the reg and the sounds it makes than you would be at 30 ft. where the consequences of a reg failure would be easier to manage. Narcosis may well be playing into it as well as in many people narcosis will exacerbate an existing emotional state. If you worry about your reg normally, you'll worry about it more when you are narc'd.
In extreme cases, that anxiety, or any other anxiety at depth can lead to a shallow breathing pattern where you do not breathe deep enough to either transfer sufficient O2 and/or exhale enough CO2. A high level of CO2 is what triggers the perceived need to breathe.
