85 ft Dive on 13 ft Pony Almost Ends Badly
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gcarter
Contributor
I was not commenting on whether or not chronic hyperventilation is a condition, or whether it can be a real problem for someone.
Air consumption of 0.7 ft3/min is not unusual, particularly among newer divers, and it does not constitute hyperventilation.
"no reason to breathe at such a ridiculous rate"
Here are my last 5 years. Your comment, intended or not, was both incorrect and condescending.
2012 - 60 dives, average SAC 0.87 ft3/min
2013 - 40 dives, average SAC 0.75 ft3/min
2014 - 55 dives, average SAC 0.67 ft3/min
2015 - 38 dives, average SAC 0.75 ft3/min
2016 - 51 dives, average SAC 0.62 ft3/min
Air consumption of 0.7 ft3/min is not unusual, particularly among newer divers, and it does not constitute hyperventilation.
"no reason to breathe at such a ridiculous rate"
Here are my last 5 years. Your comment, intended or not, was both incorrect and condescending.
2012 - 60 dives, average SAC 0.87 ft3/min
2013 - 40 dives, average SAC 0.75 ft3/min
2014 - 55 dives, average SAC 0.67 ft3/min
2015 - 38 dives, average SAC 0.75 ft3/min
2016 - 51 dives, average SAC 0.62 ft3/min
Let me clear something up. DD is a very respected diver. I wasn't trying to criticize what he did. Clearly what he was doing is very different than the average planned recreational dive.
However if you go back and read the first page there are comments made by a couple of people that there's no need to invest in large pony bottles and a 13 ft.³ bottle should be fine even for a deep dive. Then another commentor agreed with this. That's why I said I thought this would derail the thread. Not about what dumpster diver did.
The comments about hyperventilation and a misunderstanding of what an appropriate sac rate is explains my point that a lot of people don't understand aspects of gas planning a gas consumption as these are not taught routinely in open water or advanced open water.
I agree that ideally people should learn how to calculate this and figure out the size of the bottle they need. However for the vast majority of people, they unfortunately will never learn this. They should probably just get a bigger bottle so they don't have to worry about running out of air. The last thing you want is the average diver picking up 13 ft.³ bottle and taking it down there and not having enough air when they need it
Sorry that this was off topic from the initial post however it seems like it came up and seems like it's a good debate and educational experience to discuss it. Passive aggressive or insulting posts are not helpful to anyone. Rather explain why you disagree so that we can all learn.
However if you go back and read the first page there are comments made by a couple of people that there's no need to invest in large pony bottles and a 13 ft.³ bottle should be fine even for a deep dive. Then another commentor agreed with this. That's why I said I thought this would derail the thread. Not about what dumpster diver did.
The comments about hyperventilation and a misunderstanding of what an appropriate sac rate is explains my point that a lot of people don't understand aspects of gas planning a gas consumption as these are not taught routinely in open water or advanced open water.
I agree that ideally people should learn how to calculate this and figure out the size of the bottle they need. However for the vast majority of people, they unfortunately will never learn this. They should probably just get a bigger bottle so they don't have to worry about running out of air. The last thing you want is the average diver picking up 13 ft.³ bottle and taking it down there and not having enough air when they need it
Sorry that this was off topic from the initial post however it seems like it came up and seems like it's a good debate and educational experience to discuss it. Passive aggressive or insulting posts are not helpful to anyone. Rather explain why you disagree so that we can all learn.
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gcarter
Contributor
I bow to your obvious superior knowledge and judgement. I hyperventilate on all my dives, just didn't notice it. Got it.
Henceforth I will be sure to eliminate all that unnecessary and detrimental breathing from my dives.
Henceforth I will be sure to eliminate all that unnecessary and detrimental breathing from my dives.
1 ft.³ per minute is not hyperventilation. Ventilation for a person is essentially how much air moves in and out of the lungs which is mainly used to clear CO2 (oxygenation is air exchanging O2 with your blood stream). Minute ventilation is the respiratory rate (rate of breathing) multiplied by the tidal volume (the amount of air you breathe with an average breath). Minute ventilation is essentially how much air moves in and out of your lungs per minute.
This is different for everyone. The size of your lungs and the amount of air you breathe with each breath is based on many things including genetics, sex, height, weight, etc.
The SAC rate in cubic feet per minute is an expression of the amount of gas you are using each minute in cubic feet rather than liters which is what minute ventilation is usually expressed in. SAC rate is essentially used to give you your minute ventilation on the surface when breathing compressed air from a cylinder and is used to express this in a unit that is useful for us as divers so we can plan how much gas we would need.
Depending on your characteristics, that rate is not necessarily hyperventilation. Hyperventilation is when your minute ventilation is too high and you are actually over ventilating and lowering your CO2 levels too far. That is not the same for everyone. Minute ventilation requirements increase with exertion, stress, etc. If your metabolism and oxygen consumption increase, you need to eliminate the CO2 produced. If you are under water and you panic, exert yourself, etc, your ventilation requirements will increase and thus your SAC rate will increase. That is not the same thing as hyperventilation.
Source: I am a physician and regularly work with ventilators. Please excuse grammar and formatting as I am on my phone
This is different for everyone. The size of your lungs and the amount of air you breathe with each breath is based on many things including genetics, sex, height, weight, etc.
The SAC rate in cubic feet per minute is an expression of the amount of gas you are using each minute in cubic feet rather than liters which is what minute ventilation is usually expressed in. SAC rate is essentially used to give you your minute ventilation on the surface when breathing compressed air from a cylinder and is used to express this in a unit that is useful for us as divers so we can plan how much gas we would need.
Depending on your characteristics, that rate is not necessarily hyperventilation. Hyperventilation is when your minute ventilation is too high and you are actually over ventilating and lowering your CO2 levels too far. That is not the same for everyone. Minute ventilation requirements increase with exertion, stress, etc. If your metabolism and oxygen consumption increase, you need to eliminate the CO2 produced. If you are under water and you panic, exert yourself, etc, your ventilation requirements will increase and thus your SAC rate will increase. That is not the same thing as hyperventilation.
Source: I am a physician and regularly work with ventilators. Please excuse grammar and formatting as I am on my phone
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Well my sac is pretty low and I entirely enjoyed both the title and the warning of the experience shared.
Let's not end chum!
Cameron
Let's not end chum!
Cameron
CuzzA
Wetwork for Hire
Nonsense. It is you who needs to go back and read this thread. You completely made that up.
I'll quote myself to help you out.
You know what else this video illustrates? There's a lot of people spewing nonsense when it comes to gear, etc. Like "you should go out and buy a 40 cu ft pony for divers doing 60 ft. dives or you're going to die."
Cuzza, I'm sorry I must have misunderstood what that post meant. The section you quoted under your reply I must have interpreted wrong.
I interpreted what you quoted as, "people are spewing nonsense that you need large pony bottles for deeper dives." I'm interpreting this as, "a 13 ft.³ bottle should be fine for deeper dive because it's nonsense that people say you need a large one for deep dives."
I interpreted what you quoted as, "people are spewing nonsense that you need large pony bottles for deeper dives." I'm interpreting this as, "a 13 ft.³ bottle should be fine for deeper dive because it's nonsense that people say you need a large one for deep dives."
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CuzzA
Wetwork for Hire
No worries. Just setting the record straight. 
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