Metric versus Imperial System for Diving?

[dfx]

We've been using metric units almost exclusively for the last century or so, but we still find weights in pounds in the stores, at least the belt weights. Except the smallest ones. So I have 1kg, 4# and 6# weights for my weight belt.

Most people call the 4# weights 2kg and the 6# weights 3kg, though. Even if there's a 10% difference.

This has occurred to me in the Dominican Republic too. They think and measure in kilograms, but give you pound weights. It goes like this: You tell them you need 14 lbs of lead. In kg, this is slightly less than half, so they round to 6 kg. Except that they actually give you 12 lbs. Enough difference to be noticeable if you had your weight dialed in correctly...

 

[EFX]

His buddy was a regular to Malta. He was a BSAC Dive Leader and also had his advanced nitrox and extended range, so roughly similar to a PADI DM with a Tec 50 cert. The two of them jumped in first, and I was one of the last in. As I swam for the shot, the two of them were swimming back, with the second diver looking distressed and the first towing him. I watched them onto the boat and waited for an 'okay' signal. On the signal, my buddy and I descended.

I spotted the two divers had made it back into the water as they were on the wreck. Big 'okay' signal and both looking happy. Back on the boat, I went to see they were okay:

"Yeah, I'm fine. It was these weights", he said?

"Yeah?", I replied.

"Yeah! I need sixteen pounds and they had two 'stamped' on them, so I took eight."

What I wanted to say would probably upset the ScubaBoard swear-filter so much it would alert the pope if I typed it. Because I'm nice, I just said, "They're two kilo, not two pounds.".

"Yeah! I know that now..."

Funny story. I'm glad it ended well. Was this BSAC/Tec diver also blind? A 2 kilo weight which is 4.4 lbs. is both noticably larger and heavier than a 2 lb. weight. How could he get so confused? (He went down with 35 instead of 16 lbs.).

 

[Mike]

Which is why one initially assumes that even the USA ought to be able to understand and use it.

I think that's why myself and other American's on here don't really get all the Euro ranting and caring about America and the metric system. Many of us can use both systems. Really don't see why some of you are so upset that we are able to use both. Most American's have metric and standard wrenches in their garages for example able to figure out when to use one or the other without too much trouble. I have a ruler with inches one one side and metric on the other, I'm just as capable of figuring out something small in size in millimeters or inches.

The metric system is not really a big deal, nor a pressing issue.

---------- Post added October 24th, 2014 at 01:41 PM ----------

Perhaps you'd like to answer my question from post #114 then.

The metric system is probably easier to learn if you were a blank slate starting from nothing, sure.

 

[mrdre]

I think that's why myself and other American's on here don't really get all the Euro ranting and caring about America and the metric system. Many of us can use both systems.....

No, many Americans, don't. ) You could see pages and pages back people complaining about granularity, freaking out when seeing decimal point. "Using" metric system is not just having a ruler with some weird canti, deci, milli, watever-meters on it. "Using" meaning going from meters to millimeters to nanometers, instead of confining yourself to the only few memorized fractions of inches. "Using" means doing some math with it. If there is no "math" involved, then there is absolutely no difference between the systems. "Using" is when you need to roughly estimate the weight of the 6'x6'x6' full water tank. It's when the metric person tells you the rough estimate right away from the top of his head, while the imperial person will start googling and will need some computing device. So, if the imperial person can tell right away how much it would be in kilos, then we can call it "we can use the both systems", but average American can't.

 

[EFX]

There must be other possible answers besides a flat yes or no, especially when the no answer requires a cringing justification while a 'yes' stands alone shining with truth and purity.

Either it's overall easier or it isn't. What other options could there be?

A lot of people do things because they are convenient or expedient. Your suggestion that going metric would be overall easier is debateable. A previous poster who ran a car repair business confessed it wasn't easier. The change over would be painful for a lot of people at least initially. Once the dust settles we can come back and discuss how easy it actually is to use it. I agree with you on one point though, that metric is more intuitive and calculations in scale are far easier. I would love to see the diving industry here [USA] go metric. For me it's a simple selection on my DC.

 

[Mike]

Who the F cares? Doing math with it???

That's the measure of why America must convert to metric??? Oh please. I'm 48 years old, I haven't been put in jail, lost a job or missed out in anything in life for not being able to do long form calculus with metric yet. I think I'll survive.

 

[Kevrumbo]

Once again . . .what is so difficult about working with multiples or percentages of ONE???

1 bar-per-minute: the easiest reference number of all for Breathing Gas Consumption Calculations to work with! All you gotta do is multiply your depth in ATA, and you instantly know what your consumption is at that depth --essentially your depth gauge in meters is telling you your depth consumption rate because anything multiplied by ONE is itself. . ! (Click on my blog for a detailed explanation).

 

[EFX]

No, many Americans, don't. "Using" is when you need to roughly estimate the weight of the 6'x6'x6' full water tank. It's when the metric person tells you the rough estimate right away from the top of his head, while the imperial person will start googling and will need some computing device. So, if the imperial person can tell right away how much it would be in kilos, then we can call it "we can use the both systems", but average American can't.

Apples and oranges. Mike is talking about actually measuring or using a tool. You are talking about an estimate that has to do with neither and has been obtained by prior experience. I also use both systems. I work in a manufacturing plant where speed is measured in mm/min, weight in Mg (mega-grams=metric ton), and pressure in kpas's. No issue for me. When I leave the plant it's miles/hour, my weight in pounds, and tire pressure in lb/in2.

 

[agilis]

No, many Americans, don't. ) You could see pages and pages back people complaining about granularity, freaking out when seeing decimal point. "Using" metric system is not just having a ruler with some weird canti, deci, milli, watever-meters on it. "Using" meaning going from meters to millimeters to nanometers, instead of confining yourself to the only few memorized fractions of inches. "Using" means doing some math with it. If there is no "math" involved, then there is absolutely no difference between the systems. "Using" is when you need to roughly estimate the weight of the 6'x6'x6' full water tank. It's when the metric person tells you the rough estimate right away from the top of his head, while the imperial person will start googling and will need some computing device. So, if the imperial person can tell right away how much it would be in kilos, then we can call it "we can use the both systems", but average American can't.

A 6'x6'x6' full water tank? Can't be done unless you know the weight of the empty tank and if the water is fresh or sea water. The weight of the filled water tank is 72x72x72 divided by 231, with the product multiplied by 8.34 if fresh water or 8.54 if seawater, plus the weight of the tank, which was not given. Simplicity itself.

Your post suggests that the metric system is free from decimals and fractions. Not in the real world. Less prevalent, but indispensable.

 

[mrdre]

Apples and oranges. Mike is talking about actually measuring or using a tool. You are talking about an estimate that has to do with neither and has been obtained by prior experience. I use both systems to. I work in a manufacturing plant where speed is measured in mm/min, weight in Mg (mega-grams=metric ton), and pressure in kpas's. No issue for me. When I leave the plant it's miles/hour, my weight in pounds, and tire pressure in lb/in2.

Mike was talking about "using" the metric system. I just said that having a tool is not the same as using it. "Using" is when you are doing some calculations with it. If you don't then you are not really using it, it's just there. It really doesn't matter what letters are written next to what numbers. Why would there be issues?

I'll tell you when the issues come. (As an example) Years ago when I was still doing some research. We needed a device that was built to up to 1mm accuracy. The folks who were trying to build it for us used imperial system. And they would claim the device is "quarter inch" accurate, then they would go "1/16 of an inch".. damn it (I was telling them), just come and try to measure this "1/16 of an inch".. just an example of how many times we ran into problems, which costed time and money (and sometimes failed equipment). I did subcontract NASA years ago, did some little thing for them. The requirements and technical documentation were metric, then you deal with manufacturers who used imperial - and the whole fun would start. If we had to deal with any "less than an inch" accuracy things were quickly becoming messy. Yet if our partners were using metric system everything worked like charm. I can go on and on stop me..