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

[Brett Hatch]

What ever you do, take 2-3 breaths before jumping in to verify it's open.

And watch your gauge while you do it! You might have a few breaths in the hoses but the pressure will drop.

Agreed. I have never found myself in the water with a full tank that I can't breathe from, and don't intend to. Although, like tbone says, for divers who practice manipulating the valves underwater, the stakes aren't all that high, since it can still be easily fixed in-water.

Divers who are in the habit of turning the valves off after set-up, aren't in the habit of taking a few breaths before splashing, and who aren't comfortable manipulating valves in the water boggle my freaking mind. But I see it all the time, and none I've seen have died doing this yet.

 

[TMHeimer]

What ever you do, take 2-3 breaths before jumping in to verify it's open.

Yes. Bad things can happen. I've forgotten to turn my air on maybe 4-5 times back when I was fairly new to diving, but that's no problem if you're shore diving, just embarrassing to ask someone to turn it on. But you never want it off jumping from a boat.

 

[Centrals]

Divers who are in the habit of turning the valves off after set-up, aren't in the habit of taking a few breaths before splashing, and who aren't comfortable manipulating valves in the water boggle my freaking mind. But I see it all the time, and none I've seen have died doing this yet.

After setting up and turn off the tank is NOT an issue whatsoever.
It is NOT checking everything after donning the equipment is the problem.

 

[CT-Rich]

I did a shore dive with a buddy a few years ago and we swam out pretty far and he forgot to turn on his air. Fortunately he tried breathing off his reg before dumping his air, which was good, because I was a couple of yards away at the time. I have also seen divers forget they were breathing off their snorkels… plenty of ways to screw the pooch on dive (and she is a willing mistress).

I turn on my air once and leave it on. I test my BCD LP inflator and reg when I suit up. I am not a fan of negative entries anyway. I read a few account of divers hitting the water like lawn darts with their air off.

 

[Brett Hatch]

After setting up and turn off the tank is NOT an issue whatsoever.
It is NOT checking everything after donning the equipment is the problem.

Sure, point taken. I'm not trying to say that there is 1 solution here, or my solution is best.

What I intended to say is that there are many potential solutions to this problem, and yet a surprisingly large number of people don't do any of them consistently.

 

[Centrals]

Sure, point taken. I'm not trying to say that there is 1 solution here, or my solution is best.

What I intended to say is that there are many potential solutions to this problem, and yet a surprisingly large number of people don't do any of them consistently.

Too many divers have forgot their initial training regarding on pre-dive check with or without buddy!
How difficult it is to confirm to yourself that your own equipment is properly set up?
Never ever rush anyone just before the actual dive.
I can wait for others to suit up and no body can rush me unless I am ready.

 

[johndiver999]

The question is not if you should check your gear before you splash!
Has anyone ever argued that there is no need to check your gear before you splash?
Checking your gear is irrelevant to the question at hand.
For those who are not able to follow along, you should check your gear before you start the dive.

The question was: should you turn the tank off after turning it on and checking it.

I and others provided good reasons to turn it off (and some people, myself included) recommend purging the reg as well, so as to make sure that the spg reads zero when the gauge is picked up next. The purge after checking is obviously unnecessary (if you have a mechanical spg), but I do it in order to reduce the chance for my carelessness to bite me in the azzz. I won't admit to how many times I have jumped with the air off. Let's just say it was on more dives than it takes to get certified.

 

[broncobowsher]

If the valve is closed, depressurize the regulator. It is simple and safe.

If you feel you must have the regulator pressurized, just leave the valve on. 15-20 minutes, just leave it on. I've sat geared up ready to jump longer than that. Transmitter batteries last a long time, a few minutes will not matter one bit. They are likely to die of old age before over use. People have left transmitters pressurized for days at a time and they are still good. Your few extra minutes are not going to save anything.

What is gained by having the regulator pressurized and the valve off? There is a risk that you will jump in with the air off. Saying you will never forget that, you are lying to yourself. Someday you will get complacent, get rushed, or just distracted and forget. Saving air? if 3 breaths are the difference in your dive, you have other way more serious planning issues. A regulator with no air in it is an easy catch.

 

[Blackcrusader]

As I often do a lot of boat dives I setup my gear onshore. I check tank pressure. Then I close the tank valve.
When kitting up on the boat I make sure my air is on and check pressure again. After I am kitted up I do my buddy check and have my buddy check both my regulators and tank pressure and vice versa.

If you jump in with your air off it means you failed to do your checks properly. It happens. I've seen guides step off the boat and not have air turned on simply because they did not assign someone to do their buddy check.

 

[ATJ]

I remember doing a dive with a buddy at a shore dive site off Sydney called The Leap. It is a drift dive where you get in at The Leap and drift to The Steps. After you set up your gear, you leave it at the entry point and drive to The Steps, don your exposure suit and walk back to The Leap.

On this day, we did all that. I have always been in the habit of turning my valve off after setting up and checking the tank was full. My buddy wasn't (even though I had convinced him it was a good idea). As we were walking back to The Leap we could hear hissing. One of his regs had started to free flow and he had less than half a tank by the time we arrived. He had to abort the dive because it is hard enough with a full tank let alone half a tank. I think he agreed with turning the valve off after that.

While I don't depressurise my regs after turning the valve off, it is part of my routine to turn the valve on just before I don the tank. I do fill my BCD while watching the SPG before jumping in and would know very quickly if my tank is not on. Also, I fill my own tanks and they are always very close to 232 or 300 bar (as appropriate and depending on the ambient pressure) and would know very quickly if I'd forgotten to turn the valve on.