bwerb
Hoser/English Translator, eh
Sometimes Ben, you hope that the vis will clear a bit...in this case...the plankton kept on blooming...then someone silted it out 
How to safely ascend with Spare Air
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OneBrightGator:Me too Brian.
Although I opt. #1-ed it when I read the title
OBG.....
Logged Dives:None - Not Certified
How are you an instructor with no Dives?
Eiither you need to update your profile, or change your tag line.
ChrisA
Contributor
OneBrightGator:
Many random comments below. But I'm shopping for a 13 or 20 cu ft pony bottle setup.
but I do believe other solutions might fit other people
A lot of people could swim up to the surface from 20 feet without any any air. Lets say you could. If that is true then I'll bet you could swim from 40 feet up to 20 feet with no air and then if you had the spare air you could do the last 20 feet.
You should never _need_ to do this but lets say you are a PADI OW diver following the rules and staying above 60 feet. and for some stupid resaon you are OOA and buddy is gone. So you start swimming up at the 60 ft/min rate you were taught in OW class.
You will be at the surface in 60 seconds. If you breath once every 10 seconds, 6 breaths will get you to the surfce. Of cource you be blowing off a saftey stop and you be done
diving for the day. pointis that at 60 ft/min you don't need much air.
It's clear that 3 cu ft is not much but I don't buy the argument that having zero cu ft. is better then having three. Try this: Get a graph and plot "goodness" as a function of the pony bottle size. k here we go, "zero" cu ft is "very good, just what you were taught in OW class.
3 cu ft "very bad, certain death" 6 cu "small pony botlle better the nothing, 20 cu ft "realy cool". OK now we have our graph. Why doe it look like the letter "U". I would expect monotonic increase from zero to 20.
If you own a 20 cu ft bottle and reg on a slig you migh be tempted to leave it in your car or boat due to bulk if the plan is for an easy dive, so nice as the system is you will not take it with you. Spare Air is comcact and you may make a permenent part of your setup
Here is a valid use for Spar Air. I was in the dive shop and this power boat racer wants to buy a spar air. He says he puts it on his PFD right under his chin and uses it to buy him time to climb out of his boat if it flips in a race. He has to undue his three point harness and seat belt and then swimm out. I asked him why not a 40 cu ft bottle. Answer was "weight" it's a race boat
I believe that spare air was originally designed as a safety device for helicopter pilots that had to ditch in water. I should imagine they work well for that!ChrisA:
Good question... someone should look into that!!!! :blink:Viscya:
ChrisA:
A lot of people, myself included, can free dive to 20 or more, but while diving you must exhale on your way up, which somewhat limits your abilities, not to mention you're probably panicked (if you're bolting to the surface).
Your graph is inncorrect, the "very good" score should go with 80 cu. ft., i.e. the amount of gas your buddy is carrying.
The point is, a good buddy and proper planning with follow-through negates the need for a spare air, if you do choose to carry an extra air source, go with a 19 cu. ft. pony instead, we've been through the calcs before and it's the minimum amount you'd need.
A lot of people, myself included, can free dive to 20 or more, but while diving you must exhale on your way up, which somewhat limits your abilities, not to mention you're probably panicked (if you're bolting to the surface).
Your graph is inncorrect, the "very good" score should go with 80 cu. ft., i.e. the amount of gas your buddy is carrying.
The point is, a good buddy and proper planning with follow-through negates the need for a spare air, if you do choose to carry an extra air source, go with a 19 cu. ft. pony instead, we've been through the calcs before and it's the minimum amount you'd need.
OP
fisherdvm
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Ouch, you are hurting the troll with those pitch forks.... Seriously, you guys, I first went on line trying to figure out if spare air was a good thing. I really have not dove for 10 years, and I really have had only 13 dives. And yes, more than half of those dives were under PADI instructions. My instructor said you don't need to log lots of dives before you sign up for advance PADI class. My diving hobby ended quickly when internship at Tripler Army Med Cen was giving me only enough time to eat, and barely enough time to sleep... Then our little son was born.... Then you know the rest of the story.
My dilemma is that I am a wimpy 5'1'' troll who has a hard enough time lugging an 80cf alum tank - so the weight of a pony tank will probably break my back. That is why the spare air was attractive.
I am sorry for the toes I stepped on.... but I do try to be honest. Dive computers were just starting in 1993, so we were not taught to use them. I am still uncertain if it is needed if I am just going to do 1 or 2 dives a day, and perhaps no more than 40 a year. So, being a cheapskate is relative.
Now that I have inflammed alot of people, what is the best way to practice emergency ascend?? Should you practice it with a regulator in your mouth, and also when you don't have one in your mouth. At what depth do you start your practice?? I would imagine it would be most dangerous to start practicing at 100ft...
If I were to retake OW class, which one should I take. I heard that NAUI is more conservative. Our local dive shop has SSI. I am sure PADI is still good, but perhaps I should get a different perspective.
My dilemma is that I am a wimpy 5'1'' troll who has a hard enough time lugging an 80cf alum tank - so the weight of a pony tank will probably break my back. That is why the spare air was attractive.
I am sorry for the toes I stepped on.... but I do try to be honest. Dive computers were just starting in 1993, so we were not taught to use them. I am still uncertain if it is needed if I am just going to do 1 or 2 dives a day, and perhaps no more than 40 a year. So, being a cheapskate is relative.
Now that I have inflammed alot of people, what is the best way to practice emergency ascend?? Should you practice it with a regulator in your mouth, and also when you don't have one in your mouth. At what depth do you start your practice?? I would imagine it would be most dangerous to start practicing at 100ft...
If I were to retake OW class, which one should I take. I heard that NAUI is more conservative. Our local dive shop has SSI. I am sure PADI is still good, but perhaps I should get a different perspective.
The Kraken
He Who Glows in the Dark Waters (ADVISOR)
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Kim wrote"
"I believe that spare air was originally designed as a safety device for helicopter pilots that had to ditch in water. I should imagine they work well for that!"
. . . they NEVER gave me one!
"I believe that spare air was originally designed as a safety device for helicopter pilots that had to ditch in water. I should imagine they work well for that!"
. . . they NEVER gave me one!
cornfed
Mindless lemming
The point that many people are trying to make, is that sound buddy practices and dive planning are a better way to prepare for an out-of-air emergency than throwing equipement at the problem.fisherdvm:
OP
fisherdvm
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I am going to continue to be a devils advocate.
Since reading between the lines (and ignoring the pitch forks), a poorly performed ascend while holding your breath would give you a very high chance of an air embolism ( what, perhaps 30 to 100%) and blow out your lungs, right?
If you obey your no compression dive table (I am still not used to the acronyms), your risk of DCS is low (one person said 1:10000 or so). But you can not trust it completely, right?? Another person said that the risk is low if you make a slow ascend and decompression stop.
If you compare the two risks, the greatest risk would then be air embolism, right?? Perhaps a several hundred fold higher.
Risk of DCS is low if you are an inexperience diver (like me) who really should remain at 40 ft and higher, right??
The inexperience diver (like me), would be the one most likely to forget about proper emergency ascend procedure, or never taught how to do it in OW training (like me).
So, to prevent the stupid inexperienced divers (like me) from blowing his lung, even in a shallow dive, spare air might encourage him to keep on breathing, right??
So, even if the dumb guy drop his weight belt, forgot to deflate his BC, and pop out of the water from 100 ft (which he was not suppose to be down that deep anyway, right) in less than 0.5 sec, but he has a spare air in his mouth.... It has saved his life, right?? Most stupid divers like me would not be doing repeated deep dives anyway, as most of us just like to waddle at 10 to 20 ft kicking the bottom with our fins and breaking precious corals trying to keep boyant!! There aint' nothing down at 100 ft that would interest the once a year diver......
So if the inexperienced diver had another inexperienced buddy diving with him, one who is also cheap and did not have an octopus on his tank. And stupid do as stupid does, they don't pay attention to one another. Then one is out of air. Then there is the dreaded little people killer tank, the "Spare Air".. He pops it in his mouth, dump his weight belt, and his BC inflated to maximum bursting size (as he forgot proper ascend technique) - he went up to the surface - and risk a 1:10000 chance or less of DCS, but preserved his life!!
I am making this point as it seems to be counterintuitive - but as most of you are very experienced divers, you might not think of how many thousands of divers who are allowed back into the water by dive boats with very little experience or very little recent dives. I would like to agree with you guys about the spare air, but I think it would be a wimpy thing to do to avoid the pitch forks chasing this troll away.
An example is about 6 years ago while I was at a conference in Sarasota. The dive boat operator at the hotel said that he'll have no problem letting me dive, eventhough I have not dove for over 3 years. I talked to the folks at the hotel, and they said that someone died on his boat just 1 year earlier.
Yes, you can be stupid and have lots of degrees. Yes, you can be short and still be in the Army Medical Corp. Yes, I've got to be crazy to persist on my points.... But someone has to be a devils advocate.....
Since reading between the lines (and ignoring the pitch forks), a poorly performed ascend while holding your breath would give you a very high chance of an air embolism ( what, perhaps 30 to 100%) and blow out your lungs, right?
If you obey your no compression dive table (I am still not used to the acronyms), your risk of DCS is low (one person said 1:10000 or so). But you can not trust it completely, right?? Another person said that the risk is low if you make a slow ascend and decompression stop.
If you compare the two risks, the greatest risk would then be air embolism, right?? Perhaps a several hundred fold higher.
Risk of DCS is low if you are an inexperience diver (like me) who really should remain at 40 ft and higher, right??
The inexperience diver (like me), would be the one most likely to forget about proper emergency ascend procedure, or never taught how to do it in OW training (like me).
So, to prevent the stupid inexperienced divers (like me) from blowing his lung, even in a shallow dive, spare air might encourage him to keep on breathing, right??
So, even if the dumb guy drop his weight belt, forgot to deflate his BC, and pop out of the water from 100 ft (which he was not suppose to be down that deep anyway, right) in less than 0.5 sec, but he has a spare air in his mouth.... It has saved his life, right?? Most stupid divers like me would not be doing repeated deep dives anyway, as most of us just like to waddle at 10 to 20 ft kicking the bottom with our fins and breaking precious corals trying to keep boyant!! There aint' nothing down at 100 ft that would interest the once a year diver......
So if the inexperienced diver had another inexperienced buddy diving with him, one who is also cheap and did not have an octopus on his tank. And stupid do as stupid does, they don't pay attention to one another. Then one is out of air. Then there is the dreaded little people killer tank, the "Spare Air".. He pops it in his mouth, dump his weight belt, and his BC inflated to maximum bursting size (as he forgot proper ascend technique) - he went up to the surface - and risk a 1:10000 chance or less of DCS, but preserved his life!!
I am making this point as it seems to be counterintuitive - but as most of you are very experienced divers, you might not think of how many thousands of divers who are allowed back into the water by dive boats with very little experience or very little recent dives. I would like to agree with you guys about the spare air, but I think it would be a wimpy thing to do to avoid the pitch forks chasing this troll away.
An example is about 6 years ago while I was at a conference in Sarasota. The dive boat operator at the hotel said that he'll have no problem letting me dive, eventhough I have not dove for over 3 years. I talked to the folks at the hotel, and they said that someone died on his boat just 1 year earlier.
Yes, you can be stupid and have lots of degrees. Yes, you can be short and still be in the Army Medical Corp. Yes, I've got to be crazy to persist on my points.... But someone has to be a devils advocate.....
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