Metric versus Imperial System for Diving?

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Actually, while I advocate the use of the metric system, giving your tank capacity in equivalent volume at 1 atm makes a lot of sense for diving. If you calculate a volume of air needed for a planned dive, you instantly know if your tank contains sufficient air. With the 'European' system, you have to convert first. Also, tanks with the same internal volume can be rated to different filling pressures.

That said, it would be really helpful if the US adapted to the metric system (I don't blame Americans for using imperial if that's what they learned though). Apart from little annoyances, things like the loss of this 70 million $ spacecraft could have been averted: Mars Climate Orbiter - Wikipedia, the free encyclopedia
 
it's an interesting topic. being british, i use metric for some things and imperial measurements for other things. scuba has always been metric for me.


Yep.

I'm 5'7" (yes I know I'm short)

66kg

and my Ali 80 is filled to 200 bar

:confused:
 
I prefer to use the Metric system for dive calculations...but my students are Americans and they prefer Imperial. I do show them the simplicity of the Metric system then continue with Imperial. I know some instructors will dictate which system they want to teach with; as an American I approach it democratically and give the class the option...which so far always is Imperial :)
 
Actually, while I advocate the use of the metric system, giving your tank capacity in equivalent volume at 1 atm makes a lot of sense for diving. If you calculate a volume of air needed for a planned dive, you instantly know if your tank contains sufficient air. With the 'European' system, you have to convert first. Also, tanks with the same internal volume can be rated to different filling pressures.

That said, it would be really helpful if the US adapted to the metric system (I don't blame Americans for using imperial if that's what they learned though). Apart from little annoyances, things like the loss of this 70 million $ spacecraft could have been averted: Mars Climate Orbiter - Wikipedia, the free encyclopedia

Help me understand that.:depressed: Let's imagine that you have a bottle of the same volume but one can take 200 bars (3000 psi?) and the other one 300 bars ( 4500 psi?) . Would they, in US imperial, have different volumes:shocked2:? The same with a tank of 30 cuFeet: if it has an initial pressure of 3000 PSI or 2500, it has different volumes :eyebrow:, correct?

---------- Post added October 8th, 2014 at 01:23 PM ----------

I prefer to use the Metric system for dive calculations...but my students are Americans and they prefer Imperial. I do show them the simplicity of the Metric system then continue with Imperial. I know some instructors will dictate which system they want to teach with; as an American I approach it democratically and give the class the option...which so far always is Imperial :)

Makes sense. I qualified in Florida and the padi questionnaires were available in both metrics and imperial.
 
Help me understand that.:depressed: Let's imagine that you have a bottle of the same volume but one can take 200 bars (3000 psi?) and the other one 300 bars ( 4500 psi?) . Would they, in US imperial, have different volumes:shocked2:? The same with a tank of 30 cuFeet: if it has an initial pressure of 3000 PSI or 2500, it has different volumes :eyebrow:, correct?
You just play with words.
In US tank size is NOT it's physics volume inside. It is amount of air available. Manufactures set number, based on recommended pressure for this tank.
See example.
LP85 has inside physics size (sometimes called "water" size) 12.8 liters, X7-100 has 12.2 liters, but they have different manufacture air pressure.
P.S. This system very confuse me also, so for all calculations I use metric. :)
 
Was on a boat once where an American diver who - after checking the SPG on his rental gear - complained that the tank had been "filled with bar" and asked that it be drained and "filled with PSI" because he wasn't "certified to dive bar."

similarly, I witnessed a diver in Mexico end his dive because he only had 200psi left in his tank :)

...meanwhile he had a full tank.
 
Metric is a doddle to use in diving.

How many doddles in a litre?

---------- Post added October 8th, 2014 at 07:41 PM ----------

 
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I dun understand why everyone just know both system... Not really a big deal :)
 
derive and explain how to work with a metric multiplicative identity like 1 bar/min*ATA, and how you can more intuitively, quickly & easily calculate your gas consumption at a particular depth on-the-fly in metric, than by using 14.5 psi/min*ATA in US Imperial Units.

(HINT: I'll even give ya credit if you have to reference my blog).
 
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derive and explain how to work with a metric multiplicative identity like 1 bar/min*ATA, and how you can more intuitively, quickly & easily calculate your gas consumption at a particular depth on-the-fly in metric, than by using 14.5 psi/min*ATA in US Imperial Units.

I must not be as smart as I think I am... because I don't even understand what you're asking for. You've asserted that it's easier to use metric than imperial in scuba diving. I've agreed with you. And now you'd like me to defend your position by explaining it to you? Or do you want me to prove to your satisfaction that I can do "X * 1 = X" first grade math?
 
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