Air hog

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

Newbie here but we had it happen on a dive in Belize a few weeks ago. There was one diver on our boat that was obviously not comfortable in the water and was using air at a brisk clip. I saw the DM check her air and then offered her his alternate. I knew what he was doing immediately. It was not a situation where it would have ended everyones dive. The dive plan was notify the DM if air gets to 700 psi before the dive time ends and then buddy up and ascend to SS.

I thought it was a pretty neat thing to do to allow that diver to enjoy the beautiful dive a little longer. Pretty impressive on his air consumption to be able to do it without getting low himself. Didn't know this was a common or accepted practice.
 
If a tree falls in a forest and no one from ScubaBoard to hear it... is it still PADI's fault?

PS - the only ops I ever heard the 500psi thing from have been NAUI ops. Go figure.

It's always PADI's fault, who else would you blame ? :D
 
If a tree falls in a forest and no one from ScubaBoard to hear it... is it still PADI's fault?

PS - the only ops I ever heard the 500psi thing from have been NAUI ops. Go figure.

It's always PADI's fault, who else would you blame ? :D

Blame it on the Bush Administration.
 
Blame it on the Bush Administration.

3977605.jpg
 
300 psi will not allow a diver to bring somebody else up on his octo . . . at least, not from anything other than the safety stop! If you do the math, the minimum gas reserve to bring two divers up from 60 feet, assuming a 30 fpm ascent rate and omitting the safety stop, is between 6 and 700 psi in an Al80. So one should definitely be ascending by the time the tank reaches that point. It's generally taught that min gas is always at least 500 psi, simply because of the inaccuracies in pressure gauges in the lower part of their range. I have certainly seen gauges be as much as 200 psi off.
 
I've seen it happen, I don't agree with it as it can set a precedent for divers who will expect it to be the norm. I think for solid buddy teams (like TSandM mentioned) it's totally acceptable. But I think it there is a certain class of divers who will expect that their air consumption is not their problem, and will be less than thrilled when a DM calls a dive instead of sharing their own air.
 
500psi is meaningless without knowing a tank's capacity
 
I have shared air with a diver a couple of times on the way back to the mooring on HMAS Brisbane. Since we were still at 20-ish metres, and I preferred to ascend on the mooring line, I thought it best to save their air for the safety stop where their consumption would be less. I have seen SPGs out by 20bar, so I'm reluctant to run them too low. I dive with a 15l steel tank and a long-hose primary for exactly this reason... I have more than twice the gas I need, so I have plenty if I need to share. I wouldn't plan this necessarily (although if you're diving as a familiar pair, sure. And if a tip or a returning customer depends on it, no judgement from me!), but it's certainly a good alternative to an immediate ascent in some circumstances. It's also a good opportunity to practice a skill not used often.

I try very hard not to end a dive early because one person has got low-ish on air. Usually, that means being back at our ascent point at about the point where the lowest SPG is 50bar, and the two lowest divers ascending as a buddy pair on the line, and the others and I spending a few more minutes within sight of the line. That way, I can watch the first pair do their safety stop and head back to the boat, and stay with the remainder until we all ascend. Sure, it's a compromise, but everything is. I'd never split off a diver who lacked confidence, or who might go OOA, or if we weren't on a line, or if there was a current...risk outweighing the benefit. But if you have the chance to improve someone's dive by giving them an extra 5 minutes on the bottom, then they really feel like they have got good value. And as much as as being a DM is about safety and operations, it's equally about showing your divers a good time.

Dave.
 

Back
Top Bottom