Should I go Full Metric from the Start ?

[Kevrumbo]

I have read this thread with much interest. I am an Aussie and we were taught both metric and imperial in our schooling. Personally, it does not make any difference for me. I think the important thing is the user is comfortable with the system. if you are diving with Dive Masters anywhere they should be able to cope with your tank pressure in either units? All my dive computers will run either imperial or metric.

Yes, the important thing is that the user is comfortable with the system of units, but as it applies to gas planning and management, the arithmetic is a lot easier to implement in Metric, both pre-dive and during the actual dive itself.

I was certified OW and Advanced twenty years and did about 30 dives but then stopped diving. I am starting back again and have projects to do a GUE Fundamental Skills course very soon.

I downloaded the course materiel and started doing the gas management exercices. I have been doing a lot of supplementary reading also. Comparing the Metric and Imperial systems, it appears the Metric is much more simple and intuitive for all aspects of dive planning.

I am thinking of going Full Metric and for instance buying a SPG that reads in Bars instead of PSI.

I live in Montreal, Quebec, Canada, and I realize that probably most potential buddies around me will still be using the Imperial system.

Any thoughts and comments about me taking this route ?

Here's a good presentation in both US Imperial and Metric System of emergency gas planning in two separate examples of dives of 18m/60ft and 30m/100ft [skip to 10:15 mark]:

 

[KenGordon]

Metric.

If diving with people incapable of understanding that a minute into the dive with no freeflow 200 means bar not psi then multiply by 15 for them.

In the uk we have (had maybe - we've had Tories in for 7 years now) laws to force people to sell stuff priced in £/kg rather than £/lb so as to make it possible to compare prices properly. This gave rise to a set of people known as 'Metric Martyrs' Metric Martyrs - Wikipedia who are people of such unbelievable stupidity they make a SB gun control thread look like the peak of intellectual development.

I am old enough to have been taught to dive in the UK using cubic feet, and to have used imperial measurements in daily life as they were being phased out. I can deal with both. I don't visualise 3000l of gas or 120 cuft or 30m or 100ft, they are just numbers. I do know that 20m is not very deep and 40m is serious, but have absolutely no problem realising the same about 60ft or 120ft.

Don't be like the Metric Martyrs.

 

[tridacna]

@tridacna @Umuntu I know general key reference, I know certain key points but it's trying to "think" in that

I agree with you. I was brought up in metric; then came to the US and after almost 30 yrs I am completely bilingual temperature wise. I believe that unlike all the other Imperial units, Fahrenheit is actually a better scale for everyday living. (Not in the lab). Offers a much wider range of easy to relate to temps.

 

[RyanT]

Well don't you find it easier "visualizing" and using 200 times 1 bar surface pressure vs 200 times 14.7 psi surface pressure?

As for length in meters, visualize in terms of yards on a football field (1 meter is 1.1 yards) --So "First Down and (just short of) 10 meters to go". . .

Of course the math is easier in bar. But intuitively 40 bar just doesn't mean anything to me. Indeed, I do these sorts of mental shortcuts all the time so I can visualize it. @tbone1004 nailed it in his previous post by equating it to language. Unfortunately, I spent a lifetime thinking in the "language" of imperial units.

 

[Neilwood]

Temp for those who really want to get it right is for F to C is subtract 32, multiply by 5 and divide by 9.

I have a simple way in my head for it though:
Take a temp in F - say 80F.
Subtract 32 = 48
Multiply by 5 = 240 (easy mental way is multiply by 10 and half it)
divide by 9 = 26.4C (divide by 10 and and a tenth of that back)

Makes the mental arithmetic a lot easier as instead of working out what 1/9 of 48 is.

Reverse is easy as well:
Take a temp in C say 30
multiply by 9 =270 (x10 less a tenth)
divide by 5 = 54 (divide by 10 and double it)
Add 32 = 86.

The only thing to really remember is which way the 32 goes (I tend to think of it by way of the alphabet and their place in it - C is lower than F so C<F is lower therefore subtract.)

 

[lv2dive]

Stuart, I know you are a huge fan of your AI computers, and with Shearwater's entrance in the market (wait for it....) I actually agree that Shearwater AI computers are at least worthy of consideration for some people.

(Yes, I said that, and it's nowhere near April 1 )

However, when someone states they are preparing to take fundies, I do not think that is the appropriate context to recommend an AI computer.

To answer the OP's question - I'd ask if the class can be taught "bilingually" - if not, I'd learn in imperial bc it's easier to go back and learn metric.

Forget about SPGs. Get an AI computer and you can switch back and forth between Metric and Imperial at will....

 

[stuartv]

Stuart, I know you are a huge fan of your AI computers, and with Shearwater's entrance in the market (wait for it....) I actually agree that Shearwater AI computers are at least worthy of consideration for some people.

(Yes, I said that, and it's nowhere near April 1 )

However, when someone states they are preparing to take fundies, I do not think that is the appropriate context to recommend an AI computer.

To answer the OP's question - I'd ask if the class can be taught "bilingually" - if not, I'd learn in imperial bc it's easier to go back and learn metric.

Ha ha!

What is it about taking Fundies that would make a Perdix AI inappropriate? If GUE simply won't allow someone to pass Fundies using a Perdix AI instead of a physical SPG, they need to get with the times! We are closer now to 2030 than we are to Y2K....

Anyway, I haven't taken Fundies. But, from what I hear, there is a lot to be learned/gained from taking Fundies, even if you make the informed decision that you are going to forego learning the skill of unclipping an SPG from your waist, holding it up to look at, and clipping it back to your waist.

 

[tbone1004]

Ha ha!

What is it about taking Fundies that would make a Perdix AI inappropriate? If GUE simply won't allow someone to pass Fundies using a Perdix AI instead of a physical SPG, they need to get with the times! We are closer now to 2030 than we are to Y2K....

Anyway, I haven't taken Fundies. But, from what I hear, there is a lot to be learned/gained from taking Fundies, even if you make the informed decision that you are going to forego learning the skill of unclipping an SPG from your waist, holding it up to look at, and clipping it back to your waist.

the standards say "The first stage must supply a pressure gauge..." those more in with the GUE crowd may weigh in on how that is interpreted, @PfcAJ ? I think technically the AI would count as it is "supplying a pressure gauge" however that may be up to the instructor on whether they interpret that as analog only

 

[Roger Hobden]

the standards say "The first stage must supply a pressure gauge..." those more in with the GUE crowd may weigh in on how that is interpreted, @PfcAJ ? I think technically the AI would count as it is "supplying a pressure gauge" however that may be up to the instructor on whether they interpret that as analog only

Even if I dived with a computer that has Air Integration, I would use an independent SPG all the same.

The "If you need 1, then you need 2 " philosophy, I believe.

 

[tbone1004]

Even if I dived with a computer that has Air Integration, I would use an independent SPG all the same.

The "If you need 1, then you need 2 " philosophy, I believe.

then why don't we use dual SPG's in normal recreational diving? If you dive AI I recommend keeping an analog gauge on the boat, but what are you doing that is so mission critical that an SPG failure or HP hose failure *VERY VERY common* wouldn't allow you to call the dive?