Unit compatibility (DIR practitioners invited)

[NudeDiver]

maybe y'all should switch.

I agree.

I'm in the U.S. So us'all should switch.

 

[seaducer]

I agree.

I'm in the U.S. So us'all should switch.

Yeah, but you are *almost* in two other countries. So maybe your opinion shouldn't count?

Or maybe you should be nominated for Sec. of State. Or something...

 

[NudeDiver]

Yeah, but you are *almost* in two other countries. So maybe your opinion shouldn't count?

Alas....it really doesn't.

When they call the election and the loser concedes the election before your state's polls even close - you know your opinion doesn't count.

 

[Clammy]

Not sure about that. My computer reads out in 10cm increments or 1 ft increments. 10cm is 4 inches. And pressures, people seem to read in 50 psi increments maybe and 5 bar or so, so no real difference there either.

Er well I meant like I can say it's at 53 feet rather than 15 or 16 meters which could leaves you with + or - 3 feet (I know.. it's not THAT big a deal). You could go to cm but then that's just ridiculous. Same thing with analog gauges, I would think it'd be more PRECISE to read in psi on a gauge than bar without having to break it down too much. I'm probably just nit picking.

 

[Diver0001]

So, no one around here understands me when I talk in meters and bars. ....snip....

I actually have some real-world experience with this too. When I first moved to the Netherlands all my stuff was in ft/psi and all the stuff from the divers I was diving with was in m/bar.

The short story is, when in Rome, do as the Romans. It was only a matter of a couple of months before I broke down and bought an spg in bar and changed my computer to metres.

At first it was really an odd feeling. I mean 27 metres just didn't *feel* as deep as 90ft. It actually took me quite a while to adjust to that feeling.

I'm really happy I did it though, because the metric system lends itself to diving much better than the English system does.

Ok, just to answer your questions:

a). Is it typical for buddy teams of "different units" to buddy together (think charter or something) and each dive in their own units?

In my opinion you should if you intend to dive with the same buddy for a number of dives then you should get on the same page. An instabuddy is another story. If one of you has to adjust, then the metric system is the way to go. If you're using different units with an instabuddy then you should obviously get on the same page in terms of signs before hand. the sign for 1/2 air, 1/4 air can be used regardless of units and is equally well understood by all...

b). Is it more typical for someone to adjust to the other person's units?

See above

c). What if they have gauges that are not bi-calibrated?

Sort out communication before the dive, as noted above.

d). Is it DIR for buddy teams to be using different units? Do you mandate everyone be on the same units?

Why would DIR divers be special.....? Someone who is used to using the 120 rule and doing on the fly calcs in one unit isn't going to suddenly be able to make the change to the other without adding complications/risk.... Changing units will require practice.

e). Will you refuse to dive with a buddy who uses different units and refuses to switch to yours?

absolutely not.

f). Is this just a ridiculous issue that I shouldn't even consider?

There are no stupid questions.

R..

 

[NudeDiver]

The short story is, when in Rome, do as the Romans. It was only a matter of a couple of months before I broke down and bought an spg in bar and changed my computer to metres.

But the Romans are insane!!!

In my opinion you should if you intend to dive with the same buddy for a number of dives then you should get on the same page. An instabuddy is another story. If one of you has to adjust, then the metric system is the way to go. If you're using different units with an instabuddy then you should obviously get on the same page in terms of signs before hand.

I agree - but if no one is willing to switch, then oh well.

the sign for 1/2 air, 1/4 air can be used regardless of units and is equally well understood by all...

And this is what I end up doing.

Why would DIR divers be special.....? Someone who is used to using the 120 rule and doing on the fly calcs in one unit isn't going to suddenly be able to make the change to the other without adding complications/risk.... Changing units will require practice.

Because DIR has all kinds of equipment requirements. Seems like the type of units one is using could be considered an equipment requirement. I mean, if I were inventing the universe, I'd be a lot more concerned that everyone is using the same units than I would be about everyone holding their light in the same hand - for example.

 

[Diver0001]

Because DIR has all kinds of equipment requirements. Seems like the type of units one is using could be considered an equipment requirement. I mean, if I were inventing the universe, I'd be a lot more concerned that everyone is using the same units than I would be about everyone holding their light in the same hand - for example.

Well.... what I know for sure is that North American DIR divers use English and in the rest of the world they use Metric.

I would think the same things apply. Signing pressure, 1/2, 1/3, 1/4... would need to be worked out ahead of time. Stop depths would have to be noted in both systems for communication (what's 12 metres in feet out of your head...). Counting minutes in the GUE signing is universal. Other than that every diver should be (I would think) left to work out his/her deco obligation on their own initiative.

The biggest complication would be communicating depths. That's what I noticed when I moved to Holland too. All the other signs translate fairly well. But depths become a matter of "feeling" with a lot of divers and they're hard to convert in your head.

R..

 

[Clammy]

When talking about easily going back and forth between systems and simple communication and what not.. I just have to say four words.

NASA Mars Climate Orbiter.

 

[Charlie99]

I have imperial units on my SPG and computer, but have often had buddies with metric gear. It has never been a problem.

If you are too narc'd to convert using 3m = 10' and 70 bar = 1000psi then you need to ascend.

The only case I've encountered where metric vs imperial units were a problem was with a relatively new diver from the UK. He used metric at home and just could not grasp the imperial rental rig he was using in the Florida Keys. I kept simplifying until finally reaching:
depth -- shallower than 10 meters. Ignore it.
air -- 1500psi is half a tank. when the SPG is in the yellow we should be headed back. when the SPG hits the red we should be beneath the boat or preferably back on it.

That's when I realized that for the vast majority of my dives that I'd be happy with an SPG that just read "full", 1/2, 1/4, 1/8, and empty.

 

[Diver0001]

I have imperial units on my SPG and computer, but have often had buddies with metric gear. It has never been a problem.

If you are too narc'd to convert using 3m = 10' and 70 bar = 1000psi then you need to ascend.

Charlie. You're a man of precision. I know you well enough for that. 1 metre is 3.2808399 feet.

On a normal dive within the NDL's it's a minor issue to calculate with 3 but on a decmpression dive 12 metres (a common stop depth) is 36ft if you work with 3 and 40ft if you work with reality.

Frankly. I wouldn't want to be screwing up my stop depths by about a metre using the "close enough" calculation.

YYMV

R..