How long does YOUR tank last?

[RonFrank]

At 40' a bunch! Did a 2 hour dive at 15-20' and came up with around 1000lbs. There are no constant 40' profiles anywhere I dive, well maybe Perch lake but we tend to hang around 25-30' not 40' in the muck.

 

[MXGratefulDiver]

... there's a lot of slow breathers in here ... :shocked2:

... Bob (Grateful Diver)

 

[windapp]

... there's a lot of slow breathers in here ... :shocked2:

... Bob (Grateful Diver)

Keep in mind that those of us who aren't very good on air are not bothering to post.

 

[MXGratefulDiver]

Oh but you should ... otherwise it kinda skews the results.

I once did 114 minutes on an AL80 ... but my average depth was 8 feet ...

... Bob (Grateful Diver)

 

[gcarter]

My longest dive was 45 minutes. Starting pressure was 3100, ending 800, max depth 8 meters, average depth 6 meters, SAC 0.85.

Yes, I am an air hog.

 

[GrumpyOldGuy]

I usually have to pee about 3 times on a AL80 at 40'.

 

[fncrow]

I actually have a lot of dives with the profile you are asking about but cant really answer since most boats ask you to be back on the boat in an hour. I can tell you at the end of that hour i usually have about 1200-1300psi left out of 3000.

 

[vladimir]

Let's do the arithmetic. I have a SAC of between .5 and .55 in warm, clear, still tropical water that approximates a bathtub—Bonaire, say. 40' is 2.2 ATA (40/33 + 1), so I breathe about 1.2 cu ft per minute (2.2 x .55) at that depth. So an AL80 (which holds 77.5 cu ft) should last about 65 minutes (77.5/1.2), neglecting ascent and descent.

 

[AaronRiot]

Haha I'll help even things out. I've managed to suck back a tank in 35ish min in slightly shallower than 40... I was cold and working against the current for a bit. On other calmer dives I've managed 45ish in colder ~70ish degree water. Still have a lot of work to do on my breathing!

It's actually one of my big goals for an upcoming trip. Getting in and staying in a good, calm, slow rhythm.

 

[gcarter]

My longest dive was 45 minutes. Starting pressure was 3100, ending 800, max depth 8 meters, average depth 6 meters, SAC 0.85.

Yes, I am an air hog.

Probably should mention this was in 7.2 C water