Best scuba advice you’ve received

[TrimixToo]

Including the steps before the underlined:

1. Hook up your regs, open the tank and make sure the hoses are full of gas.​

2. Turn off your tank.​

3. Breathe until you've depleted the gas, counting the number of breaths.​

You now know how many breaths it takes to deplete the available gas if your tank has been turned off without your knowledge or if you've forgotten to turn it on. In this case it was three breaths.

4. Before each dive (during buddy checks), breathe from all of your regs (usually two for rec divers, three if they have a pony, may be more for tech divers).​

5. If you can breathe your three breaths from each reg without running out of gas, all of the tanks have been opened.​

This avoids a situation where your SPG reads full and a single breath doesn't indicate any issues because the hoses/first stage are loaded with gas but the tank was switched off by an absentminded DM, or you've simply forgotten about a deco bottle.

Right. The only thing to add is that you count the breaths from each reg, and use the highest number of breaths when doing the predive check. This way, you only have to remember one number.

Why would they differ? Hose length, mostly. The 7-foot hose has more gas in it than the short hose or deco reg hoses. Same could be true of a recreational setup with an octo and a pony with only one secondary.

 

[Lorenzoid]

Right. The only thing to add is that you count the breaths from each reg, and use the highest number of breaths when doing the predive check. This way, you only have to remember one number.

Why would they differ? Hose length, mostly. The 7-foot hose has more gas in it than the short hose or deco reg hoses. Same could be true of a recreational setup with an octo and a pony with only one secondary.

I have long done three full breaths off each reg. Three full breaths should be enough to drain any setup, don't you think?

 

[TrimixToo]

I have long done three full breaths off each reg. Three full breaths should be enough to drain any setup, don't you think?

For my setups and my tidal volume, yes. For others' setups and tidal volumes, I do not know. Could a small person with a correspondingly smaller tidal volume drain my setups in three deep breaths, or might it take four? What if someone had a long hose and an octo? That's why I think people should do it for themselves. Then, they *know*. In my opinion, they should know, rather than taking someone else's word for it, particularly mine. I'm just another random diver posting on the 'net, not an instructor or authority.

I think the logic of this approach is compelling, though.

I do wish I could recall whether I learned it from someone (and who, so I could give credit) or just figured it out one day, but I've been doing it for a long time.

Didn't mean to hijack the thread, BTW. To the OP, great topic!

 

[Pressurehead]

"Take a few breaths off all your regulators before you jump in"

And look at the SPG as you do it.
When we acquired our first SPG after using a J valve for so long.
We thought a SPG was the best thing since sliced bread, knowing how much gas to the Bar [psi] was "gold".

 

[Eric Sedletzky]

Best advice I ever got from my OW instructor after I qualified was "choose who you dive with carefully"

‘Ain’t that the truth!

 

[Eric Sedletzky]

And look at the SPG as you do it.
When we acquired our first SPG after using a J valve for so long.
We thought a SPG was the best thing since sliced bread, knowing how much gas to the Bar [psi] was "gold".

The SPG was supposed to eliminate the possibility of ever running out of air. You had a visual gauge of exactly how much air you had, what could go wrong? Some of the old timers response was “Great, now any idiot can dive”.
And look at today, people still run OOA!?

 

[scubadada]

The SPG was supposed to eliminate the possibility of ever running out of air. You had a visual gauge of exactly how much air you had, what could go wrong? Some of the old timers response was “Great, now any idiot can dive”.
And look at today, people still run OOA!?

I was certified in 1970 and successfully used a J-valve for 2 years. I bought my own equipment in 1972, including a SPG. It seemed wonderful to know how much gas I had. So now there are SPGS, hosed AI computers and hoseless AI computers. Still, divers run out of gas, with a very small number of exceptions, I am at a loss to explain this.

 

[Sensorone]

Dive with a redundant air supply sufficient for the depth.
Don't trust an instabuddy.
Slower is faster.
Be intimately familiar with your gear.

 

[Subcooled]

Yup.

But better: Charge all your regs. Count the breaths it takes before each one stops delivering air. Before hitting the water, open the valves and take the largest number of breaths you recorded for any reg from each one of them. For me, that's 3 full breaths for the reg with the long hose. So I take 3 breaths out of every reg I'll use on a dive, even though the deco regs take about one breath each. (In this case, keeping it simple eliminates an opportunity for error.)

Yeah, five breaths is good.
I was told to look at the SPG while testing regs. That proved usefull.

 

[boulderjohn]

I was told to look at the SPG while testing regs. That proved usefull.

I was teaching a scuba refresher group, and as they took their breaths to test their regs, I told them to look at the SPG to see if the needle was dropping. I told them if the valve was not fully open, it would drop and then recover, and if it was closed it would go to zero. As she looked at her SPG, a lady said, "So if the needle doesn't move, it's OK?" I replied, "It means that the valve is fully open."

So we went into the pool and started working on skills. Suddenly she panicked and indicated she was out of air. I shared air, and we went to the surface. I looked at her SPG, and she was indeed completely out of air.

How much air did you have in the tank when we started?" I asked.

"It was in the red," she said. "But the needle wasn't moving, so I figured it was OK."