ScubaSarus
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Do freedivers get trained on how to avaoid embolisms. The use of spare air will make this a needed skill. That's all. I'm all for a few extra breaths in an emergency.
Spare Air, Freediving, and scuba thoughts.
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Firstly everyones physiology is different and fitness levels are different - there is no reason to expect a untrained person to be able to hold their breath in a stressful situation as above for that length of time.
Secondly, there may be effort underwater, entangled, current or otherwise. In addition theres every change you'll discover you're out of air with emtpy lungs - after all, thats when you're trying to breathe in. Empty lungs ready and needing the best breath you arent going to get that long.
At 100ft the original spare air will provide you with 42 seconds of breathable air (assuming 20l/min rate). Assuming about 30ft/min ascent rate you are over 3 minutes from the surface. Assuming its a no stop dive from that sort of depth you really want to be looking at some sort of safety stop as well. Thats 5 or 6 minutes now. Even with the increased availability of air as you ascend it isnt going to let you get that much out of it. Add stress to the situation for a diver and the air lasts even less long.
The price of a spare air is actually MORE than some pony cylinder setups out there and ponys provide far more air and flexibility.
For the same price id rather know i have several minutes air than know i have a few short breaths and a LONG hold/swim.
Secondly, there may be effort underwater, entangled, current or otherwise. In addition theres every change you'll discover you're out of air with emtpy lungs - after all, thats when you're trying to breathe in. Empty lungs ready and needing the best breath you arent going to get that long.
At 100ft the original spare air will provide you with 42 seconds of breathable air (assuming 20l/min rate). Assuming about 30ft/min ascent rate you are over 3 minutes from the surface. Assuming its a no stop dive from that sort of depth you really want to be looking at some sort of safety stop as well. Thats 5 or 6 minutes now. Even with the increased availability of air as you ascend it isnt going to let you get that much out of it. Add stress to the situation for a diver and the air lasts even less long.
The price of a spare air is actually MORE than some pony cylinder setups out there and ponys provide far more air and flexibility.
For the same price id rather know i have several minutes air than know i have a few short breaths and a LONG hold/swim.
Retail prices in Canadian Dollars!
Spare Air $375.00 / 3 cu. ft. = $125.00 per cubic foot of air. At an ascent rate of 60 feet per minute, which is controlled but realistic in an emergency situation, accounting for the decreased air consumption during ascent, and a SAC rate of a high 0.8cu/min due to stress. You will require 3.6cu of air to reach the top without a safety stop. You don't have enough, so you will either run out of air on the way up, or you swim faster. Most likely you'd do both, and avoid holding your breath.
20 cu. ft. pony bottle c/w regulator, no spg $450.00 / 20 cu. ft. = $22.5 per cubic foot of air. At an ascent rate of 30 feet per minute, which is controlled and under full control without the stress of panic, and a sac rate still of 0.8cu/min just because you may be a little stressed because of the surprise. Stopping at 15 feet for 3 minutes for a safety stop, and finally ascending to the surface never exceeding 30 feet per minute. You will use 12.6 cubic feet out of that 20 cubic foot pony. Clearly giving you a good margin of safety.
A spare air is a good tool when used properly, but it will not give you what you need in scuba diving if you intend to go below 60 feet. Even then it's usefulness is questionable. It's intended use was for pilots who may have to ditch the aircraft, allowing enough time to exit and surface.
If you want to use it during free diving, that's your prerogative. I would strongly caution against this practice, as the inherent dangers are all too clear and present.
Spare Air $375.00 / 3 cu. ft. = $125.00 per cubic foot of air. At an ascent rate of 60 feet per minute, which is controlled but realistic in an emergency situation, accounting for the decreased air consumption during ascent, and a SAC rate of a high 0.8cu/min due to stress. You will require 3.6cu of air to reach the top without a safety stop. You don't have enough, so you will either run out of air on the way up, or you swim faster. Most likely you'd do both, and avoid holding your breath.
20 cu. ft. pony bottle c/w regulator, no spg $450.00 / 20 cu. ft. = $22.5 per cubic foot of air. At an ascent rate of 30 feet per minute, which is controlled and under full control without the stress of panic, and a sac rate still of 0.8cu/min just because you may be a little stressed because of the surprise. Stopping at 15 feet for 3 minutes for a safety stop, and finally ascending to the surface never exceeding 30 feet per minute. You will use 12.6 cubic feet out of that 20 cubic foot pony. Clearly giving you a good margin of safety.
A spare air is a good tool when used properly, but it will not give you what you need in scuba diving if you intend to go below 60 feet. Even then it's usefulness is questionable. It's intended use was for pilots who may have to ditch the aircraft, allowing enough time to exit and surface.
If you want to use it during free diving, that's your prerogative. I would strongly caution against this practice, as the inherent dangers are all too clear and present.
You guys didn't truly read my post. My suggestion was NOT to use spare air during FREEDIVING. That makes things alot more complicated... as you have to remember when you can hold your breath safely and when you can't.
I personally use a Spare Air while SCUBA diving at depths < 100ft. Why? Because it is very convenient, and I am aware of my abilities and limitations.
Honestly, the post is coming from a snide comment I received at a local fresh water spring that runs about 60 feet deep. The guy scoffed at my spare air. Mainly because of some posts he had read on the internet no doubt.
My retort? "Hey bud, you don't even HAVE a redundant air supply." "Not only that, but I can FREEDIVE to the bottom here at 60 feet... look around a bit, wave to you... then ascend." This spare air is so I don't have to worry about something ridiculous happening like my regulator being pulled out... choking on water... Which will most likely NEVER happen... but i'm ready.
Sooo... Perhaps the attitude i'm suggesting is... if a person MUST suck air every 2 seconds or they die... perhaps a full pony bottle is the answer.
But, realize... with the proper training and preparation... a spare air is a wonderful thing. There is NOTHING machismo about staying alive. My intention is definetely not to come across as overly confident. I'm posting to give others a hopefully unique perspective from a freediver's point of view on SCUBA.
The question is... "HAVE YOU THOUGHT IT OUT. WHAT ARE YOU GOING TO DO. HAVE YOU PRACTICED".
The truth? I've practiced safety ascents with my spare air from 100ft on the dot. Took my time. Watched my dive computer for ascent rate... I could make 3 ascents from that depth... sucked it dry on the THIRD ascent about 10 feet down.
Another reason i love it? I practiced with my dive buddy on ascents. I just handed it over to him.
I personally use a Spare Air while SCUBA diving at depths < 100ft. Why? Because it is very convenient, and I am aware of my abilities and limitations.
Honestly, the post is coming from a snide comment I received at a local fresh water spring that runs about 60 feet deep. The guy scoffed at my spare air. Mainly because of some posts he had read on the internet no doubt.
My retort? "Hey bud, you don't even HAVE a redundant air supply." "Not only that, but I can FREEDIVE to the bottom here at 60 feet... look around a bit, wave to you... then ascend." This spare air is so I don't have to worry about something ridiculous happening like my regulator being pulled out... choking on water... Which will most likely NEVER happen... but i'm ready.
Sooo... Perhaps the attitude i'm suggesting is... if a person MUST suck air every 2 seconds or they die... perhaps a full pony bottle is the answer.
But, realize... with the proper training and preparation... a spare air is a wonderful thing. There is NOTHING machismo about staying alive. My intention is definetely not to come across as overly confident. I'm posting to give others a hopefully unique perspective from a freediver's point of view on SCUBA.
The question is... "HAVE YOU THOUGHT IT OUT. WHAT ARE YOU GOING TO DO. HAVE YOU PRACTICED".
The truth? I've practiced safety ascents with my spare air from 100ft on the dot. Took my time. Watched my dive computer for ascent rate... I could make 3 ascents from that depth... sucked it dry on the THIRD ascent about 10 feet down.
Another reason i love it? I practiced with my dive buddy on ascents. I just handed it over to him.
Lightning Fish
Contributor
Really?Legionsx:
Legionsx:
Bill.
Oh well. Dunno what to say. From the quote it does APPEAR that I am talking about freediving... however the rest of the article is tying that ILLUSTRATION into scuba diving. I think perhaps you read the first sentence of the article and went into comment mode.
I suppose the format of my original post is to put people in "freediving mindset". That's why i talked about that first. I assumed if I went straight into scuba... the whole point of what a little training in freediving can do for a scuba diver... and why a spare air CAN be an overabundance of air would be lost in the shuffle.
jamiep3
Contributor
A couple of thoughts,
1. Running out of air is rarely planned. Most likely someone who has not been paying attention is going to discover this when they start to draw the last air out of the tank. They may not even have a full breath. At any depth they are probably going to suck down about half of their spare air just getting themselves back under control.
2. I agree with you that experience in freediving does help with breath control, but here again, the diver who suddenly only gets half a breath may not be in the best position to exercise it. More to the point though, it probably makes a person more comfortable in the water, which will improve the chances of them solving their problem.
3. That said, any reserve of air that you have in an emergency is better than none.
4.Most posts on this board tend to digress into a discussion of gas management. The use of spare air and or a pony assumes that you are already past that discussion. Once again when the sh#t hits the fan, some air is better than none.
Oh, and I got what you were saying the first time.
1. Running out of air is rarely planned. Most likely someone who has not been paying attention is going to discover this when they start to draw the last air out of the tank. They may not even have a full breath. At any depth they are probably going to suck down about half of their spare air just getting themselves back under control.
2. I agree with you that experience in freediving does help with breath control, but here again, the diver who suddenly only gets half a breath may not be in the best position to exercise it. More to the point though, it probably makes a person more comfortable in the water, which will improve the chances of them solving their problem.
3. That said, any reserve of air that you have in an emergency is better than none.
4.Most posts on this board tend to digress into a discussion of gas management. The use of spare air and or a pony assumes that you are already past that discussion. Once again when the sh#t hits the fan, some air is better than none.
Oh, and I got what you were saying the first time.
I happen to agree with you that practicing freediving can make a diver a better scuba diver. I haven't done it in quite awhile, (as its a bit tougher in a drysuit and very cold water,) but when I did it regularly the benefits were really significant in a very short amount of time. (Playing underwater hockey is another exercise that can make for a much better diver! 
)
It also sounds as if you've practiced with the gear you've selected, thought things all the way through together with your buddy, and have gone on practice dives together where you run through various emergency response scenarios.
Thats all good.
Your solution seems like it may work well for the type of diving you do, and thats great. I don't think, however, that you are representative of the vast majority of recreational divers out there.
Dive safe,
Doc
)It also sounds as if you've practiced with the gear you've selected, thought things all the way through together with your buddy, and have gone on practice dives together where you run through various emergency response scenarios.
Thats all good.
Your solution seems like it may work well for the type of diving you do, and thats great. I don't think, however, that you are representative of the vast majority of recreational divers out there.
Dive safe,
Doc
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