Why isn't DIR universally metric?

[Walter]

Of course you can comment, Darlin'. It just came across a tad strong. Sorry I misunderstood.

Yes, it's easy, but that's not the point. Tanks are at different pressures. Using the full volume method, I can compare all 80 cu ft tanks and know that regardless of which one I choose, I'll have approximately the same amount of air in a full tank. That's what interests me - how much it holds full. Using the empty volume method, I can compare 12 liter tanks and discover I'm comparing tanks that do not hold the same amount of air. The empty volume of a tank is of no interest to me. I prefer the method used in the US.

 

[Brian Sharpe]

So, while we're at it......why do they drive on the wrong side of the road in the UK (and some other Commonwealth countries)?

 

[Rhone Man]

So, while we're at it......why do they drive on the wrong side of the road in the UK (and some other Commonwealth countries)?

Warlike races (the British and the Japanese) travelled on the left, so that they would always have their sword arm facing anyone whomever they came across on the road.

Nations that like to surrender a lot (French, Italians, Spanish) travelled on the right, so they could quickly throw their sword away into a bush if threatened by someone they encountered on the road.

Some formerly warlike countries (like Sweden) used to travel on the left, and then switched to the right in the 50s, just to prove that socialism can work.

Why the Americans decided to travel on the right when they broke away from the UK has been a source of everlasting mystery for me. To annoy the Canadians?

Sorry, what was this thread about originally?

 

[Guy Alcala]

Calculations are actually easier in metric. But, U.S. no likey metric.

I'm not talking about the US as a whole, just a very small segment of it, DIR divers. The US won't switch to the metric system for everything until sometime after we are no longer the world's largest market and economy, and other countries aren't willing to cater to us because we're no longer the 800 lb. gorilla; instead, there'll be an 800 lb. panda. As it is, most people in the US are perfectly happy to buy their milk by the quart or gallon but their soft drinks in two liter bottles; their food in pounds/ounces but their drugs in milligrams; their gas in (US) gallons, and their tires with width in millimeters but diameter in inches; indeed, they never think about it.

For most practical purposes, there is no compelling reason (yet) for the US to switch entirely from imperial to metric. I will continue to use miles rather than kilometers and feet rather than meters, will retain my tanks with 3/4" -14 NPSM neck threads (but DIN regulator fittings), and don't even think of asking me to cut a pie into 10 pieces; I'll cut it into eight, thank you very much. No, there's no compelling reason to switch, except in cases like gas and depth calculations. Most of us can mentally divide by 10 a lot faster and more accurately than we can by 33.

But the main reason, for the DIR crowd, is sheer consistency. I mean, I've read innumerable lengthy exchanges on such minutiae as what equipment has to go in which pocket, the 'proper' way to clip off, how to mark your tanks, etc., etc. And yet, in the far more significant case of gas planning and calcs, we have two totally different systems in use, and one of them is unquestionably superior to the other _for this specific use_. Where's the logic?

If DIR divers (at least the tech ones) are expected to be able to master calculating MODs, ENDs, EADs, PO2s, ATAs, SACs, RMVs and so on, then switching from imperial to metric for gas planning/depths etc., which both simplifies the calcs and provides exactly the single, universal system that DIR stresses, is easy. Anybody who can master the above can do it.

So, what do US and them funny furrin' DIR divers do when they buddy up, their tanks and SPGs are marked differently, their gas planning numbers are totally different, as are their depth gauges? Let's do a gas check: do you mean 150 bar or 1500PSI? Oh, and negotiating average depth should be all sorts of fun. Nope, no room for confusion or misunderstandings there, because DIR means it's all _standardized_.

IMO the split is indefensible, given the philosophy of DIR. If you're going to drink the Kool-aid, you should be able to mix it in a two-liter container

Guy

 

[Hank49]

As long as it's all metric or all imperial, it's good.
Not diving related but the shrimp farmers here in Central and South America are crazy and try to mix the two.
We stock at number per meter square. We harvest and weigh total lbs per acre. We do weekly weights of shrimp body wt in grams. We weigh and sell the shrimp in pieces per lb. We do water treatments in grams per ton. It's insane. One or the other....please....

 

[rjack321]

If DIR divers (at least the tech ones) are expected to be able to master calculating MODs, ENDs, EADs, PO2s, ATAs, SACs, RMVs and so on, then switching from imperial to metric for gas planning/depths etc., which both simplifies the calcs and provides exactly the single, universal system that DIR stresses, is easy.

If you think this is what DIR is all about I wanna be a fly on the wall of your GUE-F class

 

[TSandM]

In my Cave 1 class, we had one person from Norway and two of us from the States. We traded off leading the dive, and alternated whether we did things in metric or Imperial, so everybody got a chance to do both quite a few times. I certainly didn't find it that difficult (and I now have a conversion table in my wetnotes).

I can't answer why the "powers that be" have not decided to standardize on one system, but I think they probably figure that people intelligent enough to want to dive this way are capable of learning how to do the math both ways

 

[Guy Alcala]

If you think this is what DIR is all about I wanna be a fly on the wall of your GUE-F class

I don't, but I would expect DIR-trained divers would understand the calcs (and have some understanding of the physics behind them), as opposed to the woeful ignorance of them which has been my experience of most recreational divers. As to Fundies, my buoyancy and trim are good, I can do some of the kicks (never tried a back kick), I can shoot a bag with reasonable success, gas planning's no problem, etc. How well/if I can do all of those at the same time while being part of a team and maintaining SA of my buddies remains to be seen, but one of the main reasons I'm taking Fundies is because it's possible to fail. I'm tired of paying for dive classes that don't challenge me, and where I don't learn anything I couldn't on my own (and usually already have done).

Feel free to be a fly on the wall; a good communist self-criticism session is useful for keeping hubris in check, especially when it's on video so I'll get to watch myself publicly screw up, over and over. The bigger the audience, the more humbling the experience

Guy

 

[Guy Alcala]

In my Cave 1 class, we had one person from Norway and two of us from the States. We traded off leading the dive, and alternated whether we did things in metric or Imperial, so everybody got a chance to do both quite a few times. I certainly didn't find it that difficult (and I now have a conversion table in my wetnotes).

I can't answer why the "powers that be" have not decided to standardize on one system, but I think they probably figure that people intelligent enough to want to dive this way are capable of learning how to do the math both ways

You're right, Lynne, the heck with this whole standardization nonsense. I want to mark my tanks and figure my depth in fathoms (on a logarithmic scale), and have my SPG marked in Torr

On a related subject, now that there are two (three now, I guess) DIR agencies out there, what happens when you get a UTD and a GUE buddy team, and the planned depth of the dive is between 100' and 130'? AIUI, the UTD diver would be planning on using 25/25, the GUE diver either 30/30 or 21/35 depending on the depth. Has this happened to anyone yet? I ask because we've got quite a few trainees of one or the other (or both) agencies who dive in Monterey, and I know many of them have dived together (maybe they just stayed above 100' and avoided the issue).

Guy

 

[GShockey]

You may find it interesting to know that this debate has also been shared within the GUE Instructor ranks. As instructors we are expected to be able to teach classes in both metric or imperial and when travelling we would adapt to whatever is the local "custom". As students, you may occasionaly have metric/imperial mixed teams and in that case the simplest solution is to agree before hand on what units you wish the class taught in and then ensure all students have the same gauges. We have materials available for both classes and will teach in either. I personally find metric easier even though I was on the tail end of the metric changeover in Canada and went through school with imperial. Like some others have posted, divided by ten is dead simple. However I still think miles per gallon and degrees F.....

Good luck in your class! You will enjoy it in imperial or metric.......

Best,

Guy