Do you turn the air off or leave it on after setting up on a tank?

[SlugLife]

1. Set up the equipment and check.
2. Turn off the gas because the tank would have to be transferred to the boat.
3. A slight leak on a dive boat might not be noticed by everyone. 2hrs later!!!!
4. An misplaced elbow/hand on the purge valve can result a substantial lost of your precious gas.
5. Turn on the gas and check(buddy) before you are ready to jump.

For consistency, my routine is:

• Well before the dive:
  • attach regs to tank.
  • Pressurize regs, check for leaks.
  • Close valve, and depressurize.
• As I'm getting ready to dive, or a couple minutes before:
  • re-pressurize
  • do standard checks.

The reason for the initial checks, are they can be used to discover any leaks well before the dive, and start to address them, such as something not tightened enough, a missing o-ring, etc. This saves me from 99% of unexpected maintenance issues right before jumping in the water.

The valve is closed for reasons of possible ultra-slow leaks or reg getting bumped accidentally.

The reason for depressurizing, is consistency: 1) I'm semi-nervous I'll mistakenly jump in with my valve closed, or 2) I need the routine to be CONSISTENT, meaning the valve ALWAYS needs to be opened, and there's no guessing.

I have seen this happen. On a noisy boat if the reg button gets pushed you can lose several hundred pounds before anyone figures out the noise.

With multiple scuba-tanks/regs, it may take a moment to figure out which reg is free-flowing. Even doing side-mount, solo, and only 2 potential sources, my ears don't immediately pick up which regulator it is. I guess the "hissing" means you don't really get nearly as good "spatial audio."

 

[Fishdip]

So the same dive shop that killed the girl in glacier national park also rented out gear to a inexperienced diver who ended up diving off a boat with his air off and drown with a full tank as his buddy and wife watched from the boat. So I would say leaving the air on after gear setup is the best choice along with a inflated BCD.

 

[happy-diver]

You must ride on really really long boats

with a inflated BCD

 

[DeepSeaExplorer]

If I turn the tank off after setup, I purge the reg so the SPG doesn’t indicate full. That way if I later forget, the SPG will clue me in. Turning the valve off without purging is a good way to trick yourself into thinking the tank is on.

 

[AfterDark]

99% of the time I am walking into the water not jumping. Often I set my kit up at home and drive to the dive site with the air off.
Although I have jumped into the water with my air off that is not a reason to panic. With an inflated BCD the diver will be bobbing up in a few seconds. What is there to panic about? If a diver is panicked that easily perhaps they should be rethinking their decision to be diving?

One time I did slip off a rock while putting my fins on with a deflated BCD, double steel tanks, air on. I hit the bottom at 15FSW, could not find my second stage, didn't have an octo. 2nd stage at that time and had not got to put my fins, the BCD was borrowed and the auto-inflator didn't work as fast as I was accustomed to. I did become afraid I was going to drown in 15FSW with 160 cuft of air on my back! All I could think was how embarrassing! I had been diving for 20 years at that time and was determined not to die for such a silly reason. I shucked my weight belt and floated to the surface. Then I had to ask my still laughing buddy to retrieve my weights.

That could have been a panic situation for most anyone. I'm not sure I would have been able to control my fear if my weight belt had gotten stuck or for some reason I didn't start ascending.

 

[AfterDark]

You must ride on really really long boats

In NC the boat ride can be as long as 2 hours to get to the wreck.

 

[graham_s]

Once I Set up my rig, I turn it off and leave it.
Any leaks will show up as a drop in pressure on the gauge.
The cylinder gets turned on and checked as part of the pre dive buddy checks.

 

[johndiver999]

I have seen this happen. On a noisy boat if the reg button gets pushed you can lose several hundred pounds before anyone figures out the noise.

yeah I learn most of my lessons the hard way. Divers, older ones at least, are all freaking deaf too, BTW.

 

[Dan]

Leave the air on once you set up the regs. So easy to jump in with it turned off and panic can ensue.

I have not heard one good reason on why it’s bad to leave it on. Only the misguided fear “I may lose a few psi” I say big whoop. Live to dive another a day. We are human and EASILY make mistakes like your 4-5 times.

Do you have pressure transmitter for your dive computer? Leaving the air on while the rig just sitting will waste the transmitter battery juice and shorten the battery life. I turn the air on just before I actually put the BCD on and confirm the pressure with my dive computer.

 

[johndiver999]

So the same dive shop that killed the girl in glacier national park also rented out gear to a inexperienced diver who ended up diving off a boat with his air off and drown with a full tank as his buddy and wife watched from the boat. So I would say leaving the air on after gear setup is the best choice along with a inflated BCD.

Just because one person dies, does not mean I should risk loosing my air from the tank on the ride out.

People die going out to pick up the kid's birthday cake, does that mean none of the kid's will ever have a birthday party?