A peeve but an important one - 20m is NOT 60ft!

[Kevrumbo]

I see this all the time and it drives me ****ing crazy - including in magazines that should know better. 20m is not anything like 60ft - it's 65ft. A meter is 39 ins, not 36. After a serious dive those three extra inches mount up so catch up!!!

Multiply 60ft by the quick & easy conversion factor 3/10 . . . and you get 18meters.

The "common counting numbers", also known as common cardinal numbers & sequences, for depth readings are:

Depth in Imperial Units: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 etc (by intervals of 10 feet)
Depth in Metric Units.......: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30 etc (by intervals of 3m)

To convert back & forth, just multiply by 3/10 (feet -->meters) or 10/3 (meters -->feet). It's a convenient & valid conversion approximation for all recreational depths and most technical deep diving down to 300'/90m (i.e. where the conversion accuracy error is starting to become significant).

 

[Doc Harry]

Who cares about the metric system? Anyone of importance uses Imperial units anyway.

Give the metric system an inch and it will take a mile. I wouldn't even let it get a foot in the door. No one talks metric in my yard.

 

[Luku]

Oldie But Goodie

I still like a British Pint over a 16oz Pint though

 

[Divor]

Who cares about the metric system? Anyone of importance uses Imperial units anyway.

Gimme a break.

 

[drbill]

I am glad that people who find the 3.3 approximate conversion too challenging for their arithmetic skills are willing to advertise that fact. It's good to have some insight into whom you are dealing with.

How true... but basic math is beyond many who still use the Imperial system of measure. I know, I used to teach math!

As a scientist I am constantly converting between the two systems for my research,

 

[drbill]

Who cares about the metric system? Anyone of importance uses Imperial units anyway.

And you are joking, right?

 

[Sas]

Here is a helpful guide for learning how to convert between imperial and metric, and fahrenheit and centigrade:

 

[Tanked]

Here is a helpful guide for learning how to convert between imperial and metric, and fahrenheit and centigrade:

This is AWESOME!
I love xkcd!

 

[vladimir]

Great post Sas! I have lived ouside the imperial zone for much of my life. Having a degree in mathematics, I am not challenged by conversion arithmetic; but until you really start to live metric, you will always be doing that mental arithmetic. So converting 30º C to 86º F is easy enough, but you'll only achieve complete comfort when you see 30º C and think ahhh..., instead of multiplying by 1.8 and adding 32.

 

[DandyDon]

20 meters = 43.7445 cubits