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On a single dive, do you run out of air before reaching your NDL?
Greg - 9/09/2014 6:38 AM
Category: Survey
Replies: 65

On your first dive of the day, using regular air in an AL 80 tank, do you run out of air before reaching your No Decompression Limit? Regardless of depth, altitude or temperature...leaving at least 300 psi in the tank.
Anonymous - 11/16/2014 10:27 AM
[Choose #1] I normally don’t last as long as my tank on the first dive.
TMHeimer - 10/26/2014 2:30 PM
[Choose #2] I haven’t reached either limit yet.
jnowak100 - 9/26/2014 4:06 PM
[Choose #1] for a single tank, I use a steel 120 / 15 ltr tank. but NDL is usually not the limiting factor except on deeper dives.. I am an air hog.
JeffWilsonMT - 9/17/2014 6:10 PM
[Choose #2] I dive a 100cf tank in cold water, and when I started diving the air was the limiting factor without a doubt. At about dive 130 that flipped to bottom time being the constraining factor. I recognize that’s not answering the prompt. :-)
joec1 - 9/16/2014 9:19 AM
[Choose #2] yes and No, depending on depth. I can do 65’ for 45 min and have half a tank. I think you might need to do graph or something to accurately answer this.
Brian_V - 9/16/2014 8:55 AM
[Choose #1] ...I mostly dive shallow, so the supply air is what limits the dive.
John_giu - 9/11/2014 1:05 PM
[Choose #1] considering a 30’ you could stay there all day without NDL? you might need to re-think the question.
FtMyersTom - 9/10/2014 4:06 PM
[Choose #1] I get aprox 60 to 80mins on AL80 @40ft or under with 300 to 400 left. Depends on any current or if I’m taking a hike. The only way I could reach NDL is if I went to bottom and took a nap.
Agojo - 9/10/2014 7:45 AM
[Choose #2] Occasionally use one tank for 2 dives due to deco times, just did Oriskany 126’ with AL80, 28%nitrox and surfaced after 1 min deep and 4 min safety stops with over 1200psi. Moderate current surface to 126’.
dalehall - 9/10/2014 6:29 AM
[Choose #2] Of course, it depends on depth.. Best time so far is 87 minutes on an AL80. Started with 3000 came up with 380. Depth was 35-48 feet.
Eric_R - 9/09/2014 5:53 PM
[Choose #1] Regardless of depth really doesn’t make sense to me as it’s the #1 factor. Below 20’ has almost unlimited time. Unless your not going to count a dive that’s below 20’ as a dive.LOL
KMDD - 9/09/2014 5:08 PM
[Choose #1] hardly! Give me another few years....or so.
divingbear - 9/09/2014 4:21 PM
[Choose #2] Depending on depth of coarse, best bottom time yet 2.5 hrs
artabanus4 - 9/09/2014 4:12 PM
[Choose #1] DCIEM gives me 150 mins at 40’ - I might get 60 mins of bottom time with an AL80 and exit with ~500 psi at that depth.
Smithsgold - 9/09/2014 4:01 PM
[Choose #1] I use up that air !!!!
Greg - 9/09/2014 12:50 PM
[Choose #1] On a single AL80 tank, I have always run out of air before I hit deco limits. On a 40’ dive, I can last about 60 minutes (NDL at that depth is 140 mins) with about 300 psi left.
gemiller - 9/09/2014 8:04 AM
[Choose #1] I’m so confused on how everyone is saying "No". I find it unlikely at 40’ you guys are getting 130 minutes of air time on a single 80cf alum...
JeffQCScuba - 9/09/2014 7:31 AM
[Choose #2] CC - so always run into deco way before running low on gas. Same always held true for OC, but that is because I plan my dives then dive my plan...
BillParker - 9/09/2014 7:08 AM
[Choose #2] The last thing I’m worried about is running out of air.
LatitudeAdjustment - 9/09/2014 6:47 AM
[Choose #2] Never except really deep dives but now I wouldn’t be using air at that depth