How often do you check remaining gas supplies? You vs. regular buddy vs. insta-buddy

[H2O 70]

Then, check your own every five or so breaths. Check your buddy at 1/3, then a thousand. More often if warranted by usage.

Apparently people breath around 12 times a minute.

So you're looking at your gauge every 30s? Seems a wee bit excessive.

Maybe you should get the Oceanic HUD mask with transmitter. It may allow you to see more while diving.

 

[fnfalman]

Interesting . . . I begin to see how someone could jump in with a spent tank.

We were taught to check gas -
1 - at tank hookup.
2 - at prep-to-dive
3 - at the surface
4 - after descend

Those checks let you know that you don't have a problem

Then, check your own every five or so breaths. Check your buddy at 1/3, then a thousand. More often if warranted by usage.

If a certified diver were to forget to check gas pressure upon hooking up regulator and go through the whole pre-dive checklist routine, then that diver shouldn't have gotten a C-card in the first place.

 

[idocsteve]

Check gas supply?

I wait for my AI computer to start flashing and beeping to tell me I got 5 minutes left.

 

[SolarStorm]

With my buddy, my daughter, I bought us both Atom 2 DCs and linked them for a buddy check. This did 2 things:

1. Made it very easy for her anal father to check her pressure, then ask to see if she knew aprox what she had.
2. Dont know if it was for fun or what, but I like the habit, she will now try and catch me by checking my pressure.

One thing that wasnt mentioned to us in our dive classes, so please correct me if Im wrong. I was on my 3rdish dive when I realized, I should not just be checking my pressure but using that cool feature of DTR, and monitoring that for drastic changes as well. Then if I keep track of that info in my head I can get a good bearing if it is falling dramatically and that something might be wrong. I also started a quick mental calc on 1/2 tank being approx max 1/2 dive time (including the SS) Then simply monitoring to ensure elapsed time is matching elapsed gas. All of this is quite quick to do, 20 min to 1/2 tank = another 20 max - SS and 5 min buffer. So if I calc again in 15 min and am below 1100 psi, I need to think about consumption (ie depth, and "work", or equip malfunction)

I keep telling my daughter, the difference between you and me is:

You add the numbers in your head and then check with the calculator. I do them on the calculator and then check them in my head.

 

[Bubbletrubble]

One thing that wasnt mentioned to us in our dive classes, so please correct me if Im wrong. I was on my 3rdish dive when I realized, I should not just be checking my pressure but using that cool feature of DTR, and monitoring that for drastic changes as well. Then if I keep track of that info in my head I can get a good bearing if it is falling dramatically and that something might be wrong. I also started a quick mental calc on 1/2 tank being approx max 1/2 dive time (including the SS) Then simply monitoring to ensure elapsed time is matching elapsed gas. All of this is quite quick to do, 20 min to 1/2 tank = another 20 max - SS and 5 min buffer. So if I calc again in 15 min and am below 1100 psi, I need to think about consumption (ie depth, and "work", or equip malfunction)

@SolarStorm: DTR = Dive Time Remaining? If so, then your computer would display remaining dive time as the lesser of either NDLs (no deco limits) or gas supply limits (calculated from remaining gas supply and current gas consumption rate).

Mental math is fun. I'd take it a step further and learn a little about gas planning/management. Bob Bailey (a.k.a. NWGratefulDiver) wrote a nice essay on this topic. Read it when you get the chance. You should have your daughter learn this as well.

 

[TMHeimer]

I check mine way more than necessary- My wife says I have a bit of OCD. I have only one regular dive buddy and he lets me know when he is low enough to turn the dive. Must admit, with "instabuddies" off a boat I don't check theirs- assume they know their own situation as certified divers, though at times I do signal to ask if they are OK on air and maybe tell them what I have. When I finish up DM I resolve to do a much better job when in a supervisory role.

 

[idocsteve]

I check mine way more than necessary- My wife says I have a bit of OCD.

You can't be as bad as this one guy I dived with once. He checked his gas supply like every 10 minutes! Now that might not sound too bad but I'm talking about on the boat on the way out to the dive site.

 

[Bubbletrubble]

Must admit, with "instabuddies" off a boat I don't check theirs- assume they know their own situation as certified divers, though at times I do signal to ask if they are OK on air and maybe tell them what I have.

This is interesting. I guess I don't trust insta-buddies as much as you do. Even after discussing gas management before splashing, I have no idea how much of the info the diver actually absorbed. I'll sneak a peek at his SPG a number of times during the dive just to be sure. He is, after all, carrying my backup gas.

I've had insta-buddies who have communicated incorrect gas supply numbers to me.

 

[miketsp]

Regular buddy - easy. For the last couple of hundred dives my wife always uses exactly 20bar more than me if we do a similar profile so if I'm getting to 70bar I know she's approaching 50bar. And across the scale it will be proportional.
How often to check? Totally a function of depth. Below 30m every few minutes. Below 40m probably every minute because I've seen that when I get narced what I think is just a minute may be much longer.

Instabuddy - I'll try to keep an eye on his gauge every 5 minutes for the first part of the dive until I can establish our relative consumptions. I've been caught out too often when we had agreed to signal 1/2 tank and no signal came, then the short on air signal appeared from nowhere.
I also like to look at the amount of bubbles he's putting out - nowadays I can judge a SAC fairly accurately just by watching a diver for a few minutes. It's a useful talent to cultivate.

 

[SolarStorm]

cool article! definately a read more than once to take it all in type of thing...

The other thing I did with the couple of the insta buddies I dove with. I asked one guy if he would be offended if I asked what his pressure was during the dive. (trying to be diplomatic) and he says "I better not be offended, because I AM going to ask you what yours is..." for the very reason you stated above about me carrying his disaster recovery gas.