Metric or Imperial?

[KDAD]

I'm with xs-nrg. I use the imperial system but would like to switch to the metric system . While I can see the utility in the metric system over the imperial system it is hard for me to conceptualize what the actual measurements are. I can visualize 100 feet and I can start to visualize that is 30 meters but if I go to 60 feet is hard to conceptualize that as 18 meters.

I think for me one thing I might try in the upcoming dive season is a total switch over to the metric system for dive planning and logging and see how it goes.

 

[Storker]

I can visualize 100 feet and I can start to visualize that is 30 meters but if I go to 60 feet is hard to conceptualize that as 18 meters.

Don't. Conceptualize it as "a little less than 20m".
We metric guys visualize/conceptualize round numbers (10m, 20m, 30m) just like you imperial guys do (30', 60', 100'). And that's probably the reason that a CMAS 1* diver is certified to 20m, while a PADI OW diver is "only" certified to 18m (60').

 

[The Chairman]

When my tanks are imperial, I dive imperial.

When my tanks are metric, I dive metric.

My wireless AI and I can handle both easily.

What's funny is the subtle vitriol by the "you better dive metric, or you're gonna die" crowd. It's not like we're discussing the merits of split fins and poodle jackets. Is this is the new "you need a BP&Wing" response? Dive and let dive. I simply don't get the need to turn these kinds of threads into a Battle Royale of dive philosophies. Yeah, yeah, yeah, no one said "you're gonna die", but it certainly was implied. Yeah, yeah, yeah part deux: my reference to wireless AI is certain to get a few panties in a wad. I'm popping the corn now and can't wait for the hilarity to ensue.

 

[Kevrumbo]

I'm with xs-nrg. I use the imperial system but would like to switch to the metric system . While I can see the utility in the metric system over the imperial system it is hard for me to conceptualize what the actual measurements are. I can visualize 100 feet and I can start to visualize that is 30 meters but if I go to 60 feet is hard to conceptualize that as 18 meters.

I think for me one thing I might try in the upcoming dive season is a total switch over to the metric system for dive planning and logging and see how it goes.

The common counting numbers, or Reference Cardinal Numbers, for depth seen in most Dive Tables are approximate sequences like:

Imperial US (feet) denoted by intervals of 10:
Ex): 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110 etc

Metric System goes by 3's:
Ex): 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33 etc

Practice the depth conversion factors above ("3/10" and "10/3") between the two number sequences. . . So 18 meters x 10 feet/3 meters = 60 feet
And 60 feet x 3 meters/10 feet = 18 meters.

Any "in between" number like "75 feet", just round it to the next deepest number (80 feet), and do your conversion: (80)(3/10) = 24 meters.
Another example, 31 meters round it deeper to 33 meters: (33)(10/3) = 110 feet.

 

[KDAD]

It's not that it's hard - that's why I am a convert. It's just that a different system (imperial) has been so ingrained into my understanding of measurements that I will have to follow some of your tips above to become 'fluent' in it. I have to get past the need for the equivalent measurement part.

I suspect that is why most are against it.

 

[Kevrumbo]

It's not that it's hard - that's why I am a convert. It's just that a different system (imperial) has been so ingrained into my understanding of measurements that I will have to follow some of your tips above to become 'fluent' in it. I have to get past the need for the equivalent measurement part.

I suspect that is why most are against it.

Here are the quick Pressure Conversion tips as an intermediate & understanding aid to "fluency":

Easy Imperial US/Metric Conversions pressure:

Pressure Bar multiplied by 3/2, and multiplied again by 10 gives Pressure PSI;
Pressure PSI multiplied by 2/3, and divided by 10 gives Pressure Bar.
Ex): 200bar(3/2)(10) = 3000psi ; 3000psi(2/3)/10 = 200bar.

-------------
Here's visualizing 60' to 18m again:
Depth in Meters multiplied by 10/3 gives Depth in Feet;
Feet multiplied by 3/10 gives Meters.
Example: 18m(10/3) = 60' ; 60'(3/10) = 18m

 

[EFX]

It's not that it's hard - that's why I am a convert. It's just that a different system (imperial) has been so ingrained into my understanding of measurements that I will have to follow some of your tips above to become 'fluent' in it. I have to get past the need for the equivalent measurement part. I suspect that is why most are against it.

You hit the nail on the head! The problem you, me, and a whole nation has with metric is a lack of "feel" for the measurements. While Kevrumbo presents great tips for conversions it is actually an argument against adopting the metric system. I like to have fun diving and doing conversions, albeit simple ones, is not my idea of a fun dive. The way to get a feel for metric is to simply set your computer for metric and make lots of dives. Check the depth and compare with the surface. You'll soon intuitively know what 18 meters is just like you do with 60 feet.

This reminds me of a time when the US tried to go metric by changing all the gas pumps to read in liters instead of gallons. It was weird at first but I got used to it, developing a feel for liters (not terribly hard since pop was being sold in 2 liter bottles). Then, just when I got the hang of it they went back to gallons.

 

[The Chairman]

I like to have fun diving and doing conversions, albeit simple ones, is not my idea of a fun dive.

Dive and let dive. When you read all of the stuff Kev writes to justify going to metric, I think: "Why all the bother?"

Then, just when I got the hang of it they went back to gallons.

It was those anti-litre laws. What? Rly? Those were anti-littering laws? My mistake.

 

[Storker]

Why all the bother?

 

[Kevrumbo]

You hit the nail on the head! The problem you, me, and a whole nation has with metric is a lack of "feel" for the measurements. While Kevrumbo presents great tips for conversions it is actually an argument against adopting the metric system. I like to have fun diving and doing conversions, albeit simple ones, is not my idea of a fun dive. The way to get a feel for metric is to simply set your computer for metric and make lots of dives. Check the depth and compare with the surface. You'll soon intuitively know what 18 meters is just like you do with 60 feet.

This reminds me of a time when the US tried to go metric by changing all the gas pumps to read in liters instead of gallons. It was weird at first but I got used to it, developing a feel for liters (not terribly hard since pop was being sold in 2 liter bottles). Then, just when I got the hang of it they went back to gallons.

Like learning any foreign language with English as your primary, you have to use intermediate translations for the basic vocabulary at first. As you get more fluent and experienced in conversation with the foreign language, you don't think in English translations anymore --just the context & semantics of the learned foreign language.

Another way to visualize and get a feel for distance in Meters, think of the American Football Field Gridiron converted over from yards to meters: 1 meter is approximately 1.1 yards, so the length "looks" roughly similar. . . ("First Down and 10 meters to go").