Why isn't DIR universally metric?

[rjack321]

in cave2, i had two buddies in metric and was the lone imperial...

the only real issue was gas planning in the beginning and it fell into a pretty predicable pattern, and a dual bar/psi SPG can fix that problem...

yeah in my cave 1 it was dual psi/bar (one of each) and it was monotonously predictable.

Dissimilar tanks is an annoying way to plan a cave dive no matter what the units.

 

[mania]

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

Honey, you should have already known me enough well to know that I'm not the type that tells others what they must do

Yes, it's easy, but that's not the point. Tanks are at different pressures.

Yes, but the standard on this side of the pond is 200 bars. So despite the fact that i.e. my tanks have 300 bars working preasure I still fill them up to 200 bars, so that we all can match our tanks. Quite seriously - before taking another cave class (GDI - I will come sooner or later!) I'm going to buy American gauge in psi, so matching tanks would not be so difficult (remember - I'm MA in Literature, not maths)

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)?

Small off topic. Last year I spend mainly travelling all around half of the Europe. One night I woke up and was not sure where am I. So I looked through the window and saw cars driven on the wrong side. Still I needed to check my calendar where was I, as I had 2 countries under my supervision - Cyprus and Malta. I was in Malta

 

[kathydee]

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,

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.

 

[FireInMyBones]

Has anyone purposed this to the founders? If so, what was their take? Is there an official comment?

 

[lamont]

Has anyone purposed this to the founders? If so, what was their take? Is there an official comment?

check post #50.

 

[AndyNZ]

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)

What do you mean, the wrong side?

I could cope if you said the other side, but the wrong side??? :mooner:

Driving on the left makes so much sense, in much the same way that the payload on the space shuttle is limited by the width of a horses ar$e.

The driving on the left comes from the fact that the majority of people are right handed, and when travelling on horseback in a violent medieval society.... keeping to the left means that your sword hand was between you and the person travelling the other way.

The only reason that mainland Europe switched around is because Napoleon was left handed and as a result he mandated that his armies march to the right, not the left so that he could not only protect himself, but maintain a positive (unfair?) advantage in any personal combat.

As much as I joke about the US having an English heritage, it's actually quite small - the US was much more influenced by the Spanish, French, Dutch and Portuguese. This influence, and the desire to sever all remaining links with the mother land, was the main reason that the US chose to pass on the right - despite it making no sense whatsoever.

Not all Commonwealth countries drive on the left, for example Canada is in the Commonwealth and drives on the right. Interestingly, when you look at the list of countries that do drive on the correct side of the road - there are many that were in fact French colonies that have made the decision to cast off the irrational mandate of an egotistical leftie.

Anguilla, Antigua & Barbuda, Australia, Bahamas, Bangladesh, Barbados, Bermuda, Bhutan, Botswana, British Virgin Islands, Brunei, Cayman Islands, Channel Islands, Cyprus, Dominica, Eire-Ireland, England, Falkland Islands, Fiji, Grenada, Guyana, Hong Kong, India, Indonesia, Isle of Man, Jamaica, Japan, Kenya, Lesotho, Macau, Malawi, Malaysia, Malta, Mauritius, Montserrat, Mozambique, Namibia, Nepal, New Zealand, Northern Ireland, Pakistan, Papua New Guinea, Seychelles, Scotland, Singapore, Solomon Islands, South Africa, Sri Lanka, St Kitts & Nevis, St. Helena, St. Lucia, Surinam, Swaziland, Tanzania, Thailand, Tonga, Trinidad and Tobago, Turks and Caicos Islands, Uganda, US Virgin Islands, Zambia, Zimbabwe, St. Vincent & Grenadines, Wales



Here endeth the history lesson (and the thread hijack).

 

[AndyNZ]

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.

One of the biggest challenges with mixed imperial/metric teams is actually communication.

For example, on a recent dive with an Imperial diver they indicated they had "100" for gas... not sure if it's convention to drop the last zero, but they had 1000psi (not much) but I interpreted it as 100bar (loads).

Similarly, communication depths - for some people I've dived with it seems hardwired to communicate depths in feet. Again, on a dive some time ago I was diving with someone who insisted on communicating the next stop depth (60ft, 50ft etc) underwater... which when you are at 21m and someone is telling the team to go to 60m.... if it had been just "next stop depth", I'd have gone up 3m and they would have gone 10ft.

It's these little things that you don't quite realise have a huge impact when you are doing your dive plan, so really focus on how you are going to communicate.

 

[kanonfodr]

One of the biggest challenges with mixed imperial/metric teams is actually communication.

Which can be easily solved by proper planning of the dive. Write it down on a slate if you need to, and then stick to the plan as much as possible.

That's the biggest beauty of the DIR system, IMO, is that it gives divers tools to minimize the worrying of diving with a buddy they don't understand. We all use the same method to plan the dive, communicate the dive plan, and if necessary modify the plan to the satisfaction of the TEAM.

Peace,
Greg

 

[AndyNZ]

Which can be easily solved by proper planning of the dive. Write it down on a slate if you need to, and then stick to the plan as much as possible.

Indeed - but there's still a shock underwater, despite the best of planning, when someone gives you indications of numbers that aren't what you expect. I guess it happens once, and you learn from it.

My learning from the experience is to actually make the communication independent of units as much as you can - if signal "time to turn" rather than "I'm at 70 bar", and "go to the next stop depth" as opposed to "go to 50 ft" then it causes less confusion and you can double check the team captain in your own units that you are familiar with.

 

[Guy Alcala]

The local Monterey DIR contingent has had this very discussion about switching to metric. Not sure if it will happen or not, but if it does, it will likely be done in phases.

Glad to hear it. At least the idea's out there.

Just specify the gas you want to dive not the actual depth which is generally "on the fly" anyway.

Many GUE people outside of FL don't bother with 30/30 which is essentially high flow cave mix. There's another thread here with a poll I started years ago illustrating how little 30/30 is used. And "officially" its MOD is 100ft now just like with 32%, not the old 120ft although many still use it there (ppO2 1.4).

Many GUE T1 divers just use 25/25 cause it makes sense in certain circumstances. And they might use 21/35 for nearly the same depth (but not the same profile) in other circumstances.

Yeah, I never could see a rationale for 30/30 for open water, non-overhead dives. Why on earth would you need an END of 68 feet when you can always drift and/or ascend? 25/25 to 130 ft./40m (If that's the limit) seems a lot more reasonable to me for the kind of diving I do, but then I personally find the extra expense of tri-mix tough to justify for an open-water dive to 110 feet in my local area. I and many other Monterey boat divers dive Ballbuster fairly regularly; the max. depth there is usually between 101' and 109' (Or rather, 31 and 33m), with the top of the pinnacle at 70'-75'. We dive it with Air or Nitrox with nary a problem, so spending an extra 85-95 cents/ft.^3 for He doesn't make much sense to me (not to mention $1.00 or more/ft.^3 for Argon).

UTD T1 is more limited as their card/cert doesn't technically allow 21/35, they need to be UTD T2 to officially get 21/35. Even then I don't envision many UTD divers using 21/35 for a 120ft dive. Since they "grow up" as tech divers using 25/25 its more natural to them whereas GUE doesn't really support an intermediate helium mix to the same extent. GUE has 32% to 100ft in non-strenuous circumstances, 30/30 to 100ft for high flow caves, and 21/35 for 100-150ft dives

Basically agree on w t f you're doing and its not a problem. If you can't agree on a gas, you might need to rethink how badly you want to buddy up.

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

in cave2, i had two buddies in metric and was the lone imperial...

the only real issue was gas planning in the beginning and it fell into a pretty predicable pattern, and a dual bar/psi SPG can fix that problem...

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