Air sucking pig

Last Sunday I completed the first two OW checkouts.

Near the end of the second dive, the instructor asks for remaining air. I check, and have 1200PSI. We do alternate air source ascents. My buddy donates his octo to me, and while holding the PADI handshake, we ascend. We get to the top, and the instructor tells us to go back down, reverse roles, and we're done. Well, my buddy has no problem getting down. I however, can't seem to get underwater. I tried a snorkel descent (feet in the air, kick down), but I just managed to look strange with two feet in the air kicking air to the lord. I finally get over to a platform buoy and being pulling myself down the chain. At about 8 feet, I seem to be neutrally buoyant so I begin a normal descent, however it began getting difficult to breath from my reg. I check my air pressure. 100PSI :wacko: :wacko: :wacko: .

I slowly ascend, and a few seconds later my buddy comes up to ask whats wrong. I tell him I'm out of air. He ends up going back down with the instructor and using the instructor's octo to practice alt air source ascents.

I somehow managed to use 1400PSI of air in the matter of a few minutes. Does this make sense?

I know I'm a heavy breather, but consarn.

......well, you are a new diver, so higher than average air consumption isn't uncommon.......I wouldn't worry just yet, it's too soon to pass judgement on your air consumption. Just enjoy diving, relax, and get more dives in.........soon enough you'll be in a better position to make that judgement.

I'm a bit of an air hog, so I sympathize with you.......but I've improved so that I'm about average, or a little worse than average, amid a group of divers. Where possible I dive my own tanks to even the odds.......so I use LP 120's and HP 120's and HP 130's........in those cases I manage to keep up with the group or do better than the group.........so it's possible you may end up being someone who just uses more air than average........don't let it worry you, as long as you can handle a higher-capacity tank, you'll be able to keep pace with other divers.


Karl

I'm confused. Am I missing something here:

1. Toward the end of your second dive, you check and see that you have 1200psi
2. You take your buddies alternate and ascend
3. You try to go back down and can't realizing you have only 100psi left in your tank.

I am confused as to how you could breath 1100 psi on the surface? Perhaps you had a leak somewhere? Although with the little amount of time you said elapsed, it have to be a major leak. With that being said, I would think you would have almost hyperventilating to breathe 1100psi on the surface in a short amount of time.

Did you have the same trouble on your 1st, 3rd & 4th dives? If so, I recommend to my divers to work on improving your cardiovascular (i.e. walk more, jog, aerobics...etc.). Also, what scubafanatic is also another way to extend your bottom time. Some of my dive buddies are very tall big guys and they just use more air. They just have bigger bodies; so, they use bigger tanks! I think no less of them for using bigger tanks...but they think lesser of me because I can't LIFT THEM!

With what you described, it doesn't seem likely you used up 1100psi. Are you sure you read your gauge correctly...you sure 1200psi wasn't 200psi? Seeing that it was your very first OW dives, I'm sure this could have easily been overlooked, especially if your instructor was waiting for your response.

Also, if you had to fight to get down you might be underweighted. Make sure to let alot of water in your wetsuit before you descend, exhale as your deflate your BC, ...


Ideally you should be out of the water with 500psi or more...your tank will be a tad heavier than it was at 100psi, but it sounded like you were having extreme difficulty getting down, so I'm sure you were underweighted.

Anyway, keep an eye on your gauges and dive often and safely.




jason

It's quite possible that your second stage free flowed when you dropped it from your mouth, it's not unthinkable that with all you had going on (task loading) you wouldn't have noticed it bubbling off behind you for a bit. I would expect your instructor to turn it mouthpiece down to halt the freeflow but his attention may have been on the two mouths, and the regulators in use, making a shared-air ascent.

You're SAC will improve regardless of whether you huffed it down or lost it somewhere else, and your situational awareness will as well. Congrats on the OW, it's a life-changing experience.

I think it is strange asswell to complete two dives and have 1200psi left and then suck that down in two minutes ?

If you really suck that much air wouldn't your tank have been empty after two dives ?

Either you had a freeflow, misread the guage, or your sense of time was screwed up.

I'd just be aware that something unexplained happened and keep on training.

It's been a long time since I've personally dove a mecahnical guage... but I do still teach my students (who almost always have the store's rental guages) to occasionally tap the face of the gauge. They can/do sometimes stick.

Is it possible that was the source of the problem and the solution to the mystery?

learn-scuba once bubbled...
It's been a long time since I've personally dove a mecahnical guage... but I do still teach my students (who almost always have the store's rental guages) to occasionally tap the face of the gauge. They can/do sometimes stick.

Is it possible that was the source of the problem and the solution to the mystery?

Click to expand...

I recorded a bottom time of 20 min on my first dive. I also noted beginning/ending air pressure of 3000/1500.

Second dive lasted 43min. I do not think it would be possible that my air consumption improved that much. A sticking guage is a very likely cause.

GlockDiver once bubbled...


I recorded a bottom time of 20 min on my first dive. I also noted beginning/ending air pressure of 3000/1500.

Second dive lasted 43min. I do not think it would be possible that my air consumption improved that much. A sticking guage is a very likely cause.

Click to expand...

That 43 minute dive eliminates the freeflow and misreading the guage.

A 5000psig guage hanging up for about 800-900psig is not an everyday thing, but certainly not unheard of.