Are bad tanks possible?

[nachosaregood]

I just had an odd experience on a recent dive. As i started to decend, I could not get a full breath of air. I could get what seemed like a 3/4 inhalation, then there was nothing left. It seemed like the tank was out of air or very low. I tried the back up and the same thing. I surfaced, had my buddy make sure the valve was open and we checked for leaks. Second attempt to decend, same thing. So I bailed on the dive. I only have about 50 dives, so I still have a lot to learn, but the dive master said I was panicing and that caused the problems. I was only down about 15 feet and I was getting enough air to deal with the problem, so I don't think I was panicing (maybe I was???). Back on the boat, the regulator seemed fine when I took a few inhalations and the boat captain and I gave it a visual check. Another weird thing was the tank was at 3100 psi when I entered and after this 5-7 minute episode it was under 2500 psi.


Anyway, after all of the rambling, does any of this make sense???


Also, I swapped tanks for the next dive and all was fine.

 

[Luckless]

Don't forget to double check your gauges to insure they are functioning properly. From playing paintball I learned that just because a gauge says 3000psi, doesn't mean it is actually 3000psi.

What size tank was it, and what is the normal rate of pressure drop? If you are losing pressure it means the air is going somewhere, so get yourself a tub of still water and track down the bubbles.

 

[yousmellsfishy]

Could it be that the first few hundred pounds does, in fact, go quick? It seems to me that whenever I check my gauge for the first time on a dive, I'm always surprised at how much gas is gone so early on. Last month in Cozumel, I was diving with steel 120's filled to around 3400 psi. On each dive, when I would look at my gauge for the first time, it would be at 2700 or so, far sooner that I would have thought. Then, after that, the pressure seemed to drop at a rate that seemed more appropriate. Maybe it takes me a few minutes to my consumption under control. :sad2: