Unit compatibility (DIR practitioners invited)

[NudeDiver]

4 You must have a pretty poor memory.

I do - and I don't want to use up what little memory I have memorizing any more trivial stuff than I have to

 

[TSandM]

Just to answer the DIR part of it . . . For my Cave 1 class, we had two Imperial divers and one metric diver. We alternated the dives -- One was calculated in bar and meters, the next in Imperial, and whoever was leading had to do the calculations, whether it was his native system or not. So I would say that, at least for the cave folks, they expect us to have some facility with both.

However, I'm hopeless at understanding what a 15l tank is

 

[Kern]

The US will NEVER convert to metric. It's just to euro-centric for us to consider.

Richard

This will explain why you went straight to $ & cents instead of using LSD.

 

[grazie42]

So - now the 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?

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

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

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

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

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

I'm just curious - mostly because of the incident I described in the opening paragraph.

a) For a reef-dive it wouldn´t matter all that much but I would want a common language for units before I get wet...
b) Thats how I would do it, its not that hard after all.
c) Then someone will need to learn basic math.
e) No, I have and will dive both.
f) It is an issue to consider, specially with "overzealous" DMs, you want them to be aware that your are diving properly () even if they are not...

 

[Sas]

I have only ever dived with one person who used imperial - a guy from the US on holiday. It was not really an issue as we discussed what our max depth and turnaround pressure was going to be for us, as well as what depth we'd be doing safety stops. The DM assisting on the boat who reviewed the plan after we'd discussed all this actually knew all the conversions so after all our planning we could have just asked him For more complicated diving then I would spend a fair bit more time working things out but I don't do complicated diving so it is not an issue for me yet. Good question though as I hadn't thought much about it before. I think with anybody who is not local that I may buddy up with, I will check with them what they have their computer set to.

Also for those that struggle with metric I found a guide that may help :

 

[seaducer]

So people in the U.S. should force themselves to use a screwy measurement system just because the country is backward, relative to the rest of the planet? Screw that

Nope, you use whatever system you like. However, if it is the other system in common use where you are diving, then it is your responsibility to be able to do the conversions.

As far as diving with someone who uses the other system than you, as long as you each know how deep you are, what difference does it make? If I am ok being at 31 feet and you are ok being at 10 meters, can we hear the tree falling 6000 cubits away in the forest?

 

[vondo]

So, no one around here understands me when I talk in meters and bars. I don't understand them when they talk in feet and PSI. Not that I really care - but it seems like it could be an issue. On one dive, I was with an instructor for a drysuit course, and she looked at my computer at some point early in the dive, saw that it read 200 on the pressure, and thumbed me to the surface. She thought I was low on air, because she didn't know it was 200 BAR not PSI. No problem - I explained, and back down we went.

So - now I am wondering, what the usual is. Obviously, in the ideal world, buddy teams would be using bars and meters - eh, I mean - the same units. Equally obviously, there are situations where this isn't going to happen. When diving, I think in certain units, and someone else thinks in other units. I imagine that MOST people are not comfortable switching units and adjusting thought processes, and many of those people are not going to be willing to do so. I know I'm not.

So - now the 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?

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

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

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

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

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

I'm just curious - mostly because of the incident I described in the opening paragraph.

I'm one of those weird Americans who dives metric, so it's on me generally to make sure that people I dive with know that and to do the rough conversions. It's not so tough. For recreational reef diving just approximate 1m = 3ft and 1 bar = 15 psi and you're pretty much there.

We'll agree on a turn pressure in PSI and then I just convert. But yeah, sort this out *before* you get in the water. Generally I don't look at my buddies gauges or expect them to look at mine, so it's not really an issue.

 

[b1gcountry]

I did the Kessel Run in less than twelve parsecs!

 

[Walter]

Saspotato, interesting charts, they may get pulled. In temperature, when you say -40 degrees, you never have to specify which system.

If I am ok being at 31 feet and you are ok being at 10 meters

A common misunderstanding. Your depth (in either system) is not really your depth, it's merely an expression of pressure in fsw or msw (could be ffw or mfw), it is not the linear distance to the surface. By defintion 1 ATM = 33 fsw = 10 msw.

 

[SparticleBrane]

However, I'm hopeless at understanding what a 15l tank is

You have single 95s that you use, yes?
There you go.