Why isn't DIR universally metric?

[Guy Alcala]

Guy,

I share your sentiment – I’m new to the path and after a pretty thorough investigation, the lack of unit standardization was the only logic glitch I could find in the DIR system.

I understand the reason for two unit systems, but I agree the lack of standardization seems inefficient and out of character, when one universal system (metric) obviously makes more sense for calculations.

I do consider myself lucky that unit discrepancy is my only contention with the path -- it's a small price to pay for this tasty Kool-Aid that I’m guzzling .

I’ll be thrilled if our local Monterey chapter switches to metric. But we will still have to learn the imperial calculations to dive with the rest of the country.

:Kissy:Kathy, we're going to have to do some diving together As to the rest of the country, we're in California. Like many other innovations that began here, if we start it here it may gradually roll its way eastwards. Especially since, unlike many of the trends that get started here, the logic underlying this one is irrefutable (and totally DIR).

Guy

 

[Blackwood]

Thats all very well for people with big brains like you & your friends. People with small brains like my friends & I, just thank heaven they took our LSD away & gave us metric money. Just like you chaps.

LOL.

Seriously, though. Both systems are rated in volume per pressure. L/bar, CF/PSI. It makes little difference to me.

 

[rjack321]

Assuming neither of you has full tanks beforehand, I agree, but that's often not the case. Who wants to throw away expensive gas?

Its not a problem switching from 25/25 to 21/35 or vice versa. IF you each only have one set of doubles with a different mix in them the problem is not the agencies its that you need more doubles.

I have 6 sets with 32%, 25/25, 21/35, 18/45 and rarely 15/55 in them depending on what's going on.

Then ISTM GUE/UTD should require SPGs to be dual reading (and judging by all the ones I've looked at, much harder to read _either_ scale); otherwise that doesn't resolve the problem that I mentioned and AndyNZ encountered. If DIR equipment configurations are supposed to be standardized so that in an emergency you know exactly how your buddy's equipment is set up, then if you have to check their gas supply for any reason you shouldn't have to say to yourself, "let's see, is this particular gauge marked in PSI or BAR? H'mm, I _think_ it's PSI but I'm used to thinking in BAR, so even though I know exactly what equipment they keep in each of their pockets (which I'll almost certainly never need), I need to spend some mental effort trying to convert between the two units when I should be concentrating on dealing with the problem." I don't know about you, but this seems much less than optimum to me, violates the KISS principle and is a glaring exception to the DIR philosophy.

Guy

If you can't tell a PSI from a BAR reading SPG from one another you got problems. I only check my own backgas gauge maybe 6-8 times a dive there's no need for you to check it on my behalf, I know how much I have thank you.

 

[Guy Alcala]

Its not a problem switching from 25/25 to 21/35 or vice versa. IF you each only have one set of doubles with a different mix in them the problem is not the agencies its that you need more doubles.

I have 6 sets with 32%, 25/25, 21/35, 18/45 and rarely 15/55 in them depending on what's going on.

That may be me someday, but not today.

If you can't tell a PSI from a BAR reading SPG from one another you got problems. I only check my own backgas gauge maybe 6-8 times a dive there's no need for you to check it on my behalf, I know how much I have thank you

Of course you've got problems, in an emergency - any number of accidents, flying, diving, driving etc, have occurred because the person using the gauges expected to see one thing and didn't, because they were hurried, nervous or flustered, interpret what was actually there. Why introduce any more task-loading unnecessarily? You may be able to read your gauges when you're well, but aren't we supposed to plan for emergencies when one buddy may be incapacitated?

The main difference I see between PSI and BAR-marked SPGs is that BARs use two or three characters, and PSI uses three or four. Easy to forget in a hurried look.

Now, since we're all supposed to know how much gas we have at all times, maybe we should do away with SPGs entirely, as they just provide multiple additional failure points But the logic behind standardizing units, gas or otherwise, still remains.

Guy

 

[lamont]

If DIR equipment configurations are supposed to be standardized so that in an emergency you know exactly how your buddy's equipment is set up, then if you have to check their gas supply for any reason you shouldn't have to say to yourself, "let's see, is this particular gauge marked in PSI or BAR? H'mm, I _think_ it's PSI but I'm used to thinking in BAR, so even though I know exactly what equipment they keep in each of their pockets (which I'll almost certainly never need), I need to spend some mental effort trying to convert between the two units when I should be concentrating on dealing with the problem." I don't know about you, but this seems much less than optimum to me, violates the KISS principle and is a glaring exception to the DIR philosophy.

Why do you need to check their SPG?

And if its important to be able to check an SPG, why isn't there a backup SPG in the DIR gear configuration?

 

[rjack321]

Of course you've got problems, in an emergency - any number of accidents, flying, diving, driving etc, have occurred because the person using the gauges expected to see one thing and didn't, because they were hurried, nervous or flustered, interpret what was actually there. Why introduce any more task-loading unnecessarily? You may be able to read your gauges when you're well, but aren't we supposed to plan for emergencies when one buddy may be incapacitated?

The main difference I see between PSI and BAR-marked SPGs is that BARs use two or three characters, and PSI uses three or four. Easy to forget in a hurried look.

A) I've never checked a buddies SPG except secretively a few times with new buddies diving recreationally when I didn't quite trust their ability to keep tabs on their own gas. And a few times helping out in courses because students often get too task loaded to check, although its really the instructor responsibility.
B) I have asked a buddy a few times just to be able to estimate a turn around time/distance recreationally (going in a big loop)
C) Lastly and most importantly there is never a rush if everyone has a working reg in their mouth. If someone doesn't, well confirming that fact with their own spg is kinda silly.

 

[kathydee]

:Kissy:Kathy, we're going to have to do some diving together As to the rest of the country, we're in California. Like many other innovations that began here, if we start it here it may gradually roll its way eastwards. Especially since, unlike many of the trends that get started here, the logic underlying this one is irrefutable (and totally DIR). Guy

I'm not lookin' to reinvent a highly functional system that I've barely glimpsed - so I'll leave you to your tirade .

But just for kicks & old time sakes, I could be talked into hooking up my bars gauge & resetting for meters/Celsius to join you for an afternoon dive someday (if that's what you are running ;-). It would be good practice to play with the numbers anyway.

 

[Kevrumbo]

Why do you need to check their SPG?

And if its important to be able to check an SPG, why isn't there a backup SPG in the DIR gear configuration?

A) I've never checked a buddies SPG except secretively a few times with new buddies diving recreationally when I didn't quite trust their ability to keep tabs on their own gas. And a few times helping out in courses because students often get too task loaded to check, although its really the instructor responsibility.
B) I have asked a buddy a few times just to be able to estimate a turn around time/distance recreationally (going in a big loop)
C) Lastly and most importantly there is never a rush if everyone has a working reg in their mouth. If someone doesn't, well confirming that fact with their own spg is kinda silly.

On a three-man team gas-sharing egress from an overhead, it's always good to see how gas much your donor has on his SPG as well as your other teammate, just in case you have to switch donors on the way out.

I'm not lookin' to reinvent a highly functional system that I've barely glimpsed - so I'll leave you to your tirade .

But just for kicks & old time sakes, I could be talked into hooking up my bars gauge & resetting for meters/Celsius to join you for an afternoon dive someday (if that's what you are running ;-). It would be good practice to play with the numbers anyway.

Play this number game: very easy to track a slow 1m/min ascent rate from a 6m Safety Stop (or final Oxygen deco stop) to the surface . . .simply for every 30sec, just make sure you're ascending by a delta interval of 0.5m.

 

[lamont]

A) I've never checked a buddies SPG except secretively a few times with new buddies diving recreationally when I didn't quite trust their ability to keep tabs on their own gas. And a few times helping out in courses because students often get too task loaded to check, although its really the instructor responsibility.
B) I have asked a buddy a few times just to be able to estimate a turn around time/distance recreationally (going in a big loop)
C) Lastly and most importantly there is never a rush if everyone has a working reg in their mouth. If someone doesn't, well confirming that fact with their own spg is kinda silly.

D) either you've got enough gas to exit or you don't. either a tank has breathable gas in it, or it doesn't, and zero is the same in bar and psi...

also: i thought about changing my depth gauge over to meters during cave2, but it was ultimately less error prone to stick with feet on the gauge and to communicate in meters. if you're at 40 feet and someone you know is in metric gives you "move up to 9", i'll bet that 9 msw == 30 fsw without even thinking about the math...

on the other hand, putting the gauge into metric, i'm likely to decide to stop at 19 msw or something like that...

 

[rjack321]

D) either you've got enough gas to exit or you don't. either a tank has breathable gas in it, or it doesn't, and zero is the same in bar and psi...

also: i thought about changing my depth gauge over to meters during cave2, but it was ultimately less error prone to stick with feet on the gauge and to communicate in meters. if you're at 40 feet and someone you know is in metric gives you "move up to 9", i'll bet that 9 msw == 30 fsw without even thinking about the math...

on the other hand, putting the gauge into metric, i'm likely to decide to stop at 19 msw or something like that...

LOL "move up" is pretty non-denominational.