The great Spare Air / SpareAir topic
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Thanks dude! I am glad to have found a friend here. I do have another gas question for the board masses: Propane! What is the best way to attach a propane tank to my rig? I have recently purchased a "ScubaPro Sub-Aqua Grill". This is a very nice grill and can toast up a bunch of hotdogs and burgers at depth. (as well as the buns) BUT: just when the grill gets hot and heavy, I run out of gas... Anyone know a way I could carry a streamlined propane-pony? As a newer diver I figure that I will never try to toast weenies any deeper than 130fsw. But who knows what the future will bring.? Tech diving is not that interesting to me at this point, but I do have a dream of snackin' on a weenie on the deck of the "Doria". Peace all, and thanks for your time, Gallo (who learned everything he knows reading Clive Cussler novels.)
Yeah I hope to fit in I suppose. But after this last lenthy exchange I figure I am branded as "the outta O2 guy" . I understand how people could be shocked that a diver would suck the tank dry. But there were a few issues that I did not bother to explain. We were over 100 miles from land. The current was very intense and seas were high. The dive master told us that we would be unable to breathe on the surface ("unless you have a four foot snorkle...") Me and my buddy (a dive master) ascended on the line with over 700psi each. Upon reaching 15 feet we found a few divers hanging on the ascent line. One of them was playing with his reel..trying to re-spool. The boat was leaping in and out of the water in an alarming way. My bud and I had to wait while he and all the other divers pulled themselves onto the deck. I can tell you that if anyone let go of the line they would have been lost in the seas. (this dive outfit loses a few once in a while) My dive bud and I did manage to climb on board our boat, but with a few scraps of air between us... I figure we did well. I thank her for the shared air and calming effect. Peace to all, DG
Cool dude (or dud-ess?). I only posted the last because I was tired of being labeled a putz. Lets move on to new topics soon. I declare this thread DEAD!! (Frankly I have no time for it. ) I'm too busy creating a highly advanced bottom timer /pager/cell phone combo. This awesome divice will allow your LDS to page or call you when you are in danger of exceeding your no-deco limit. It takes all the risk out of diving! Thanks again, DG
HA! Yeah I hear ya.. Oh and BTW it's dude... And threads die quick unless you mention something not to do with diving.. Then they go on for ever... IE.. Hottest Male/Female.... uh... Wanna play a game.... Anything to do with IRAQ.. Oh and any social event... hehe.. Go figure.. A scuba board with biggest topics and most threads in the Non Diving related section.
Anyhow....
-D-
Anyhow....
-D-
scubadudee
Guest
Hi,
I was wondering if you dive using normal air mix.
On unexpected circumstances, maybe like a strong current dragged you deeper thus past your NDL....would this help by a quick decomp for about 5 minutes ?
I was wondering if you dive using normal air mix.
On unexpected circumstances, maybe like a strong current dragged you deeper thus past your NDL....would this help by a quick decomp for about 5 minutes ?
Without getting into my views on "accidentally" getting low on air or incurring a decompression obligation, let's plug some numbers.
Looking at the web site, Spare Air's come in 1.7 and 3.0 cubic foot models.
Let's say your gas consumption rate at the surface (1 ATM) is 25 psi/minute on an Aluminum 80, which is pretty average. That equates to .65 cubic feet of gas per minute. If you need to stay at 15 feet, where the pressure is 1.45 ATM, your rate of gas consumption will now be 1.45 x .65 or .94 cubic feet per minute - add just the tiniest bit of anxiety and we can just say 1 cubic foot per minute. So, you'd need 5 cubic feet of air for a five minute stop at 15 feet, and that doesn't leave any for a nice slow ascent.
In fact, since you brought it up, let's look at the Spare Air for use as an emergency ascent bottle, it's principle advertised use. If you are at 100 feet, for example, how much gas do you need to make a normal ascent? At 30 feet per minute, you'd need 200 seconds, or 3.33 minutes for the ascent, with an average depth of 50 feet, or 2.52 ATM, so, if you have a normal breathing rate you'd need about 3.33 x 2.52 x .65 = 5.44 cubic feet of gas just for the ascent. A three minute safety stop would bring the requirement up to over 8 cubic feet. That's a bit more than is in a Spare Air.
This should shed some light on the popular moniker among the jaded in the diving community for the Spare Air, which is "Spare Death."
Rick
Looking at the web site, Spare Air's come in 1.7 and 3.0 cubic foot models.
Let's say your gas consumption rate at the surface (1 ATM) is 25 psi/minute on an Aluminum 80, which is pretty average. That equates to .65 cubic feet of gas per minute. If you need to stay at 15 feet, where the pressure is 1.45 ATM, your rate of gas consumption will now be 1.45 x .65 or .94 cubic feet per minute - add just the tiniest bit of anxiety and we can just say 1 cubic foot per minute. So, you'd need 5 cubic feet of air for a five minute stop at 15 feet, and that doesn't leave any for a nice slow ascent.
In fact, since you brought it up, let's look at the Spare Air for use as an emergency ascent bottle, it's principle advertised use. If you are at 100 feet, for example, how much gas do you need to make a normal ascent? At 30 feet per minute, you'd need 200 seconds, or 3.33 minutes for the ascent, with an average depth of 50 feet, or 2.52 ATM, so, if you have a normal breathing rate you'd need about 3.33 x 2.52 x .65 = 5.44 cubic feet of gas just for the ascent. A three minute safety stop would bring the requirement up to over 8 cubic feet. That's a bit more than is in a Spare Air.
This should shed some light on the popular moniker among the jaded in the diving community for the Spare Air, which is "Spare Death."
Rick
I've always preferred "Scarce Air"
Roak
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