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 ?
If you understand the GUE gas management material better, then stay with Metric from the the start. . . especially if you plan to travel & dive overseas internationally where you find mostly European & Asian Dive Buddies.
Here are some practical Imperial US/Metric Conversions which you will use a lot:
1 cubic foot is 28.3 liters.
1 lb is approx half a kilogram; (1 kilogram is actually 2.2 lbs).
2 inches is approx 5 centimeters (1 inch is actually 2.54 centimeters);
4 inches is approx 10 centimeters;
so 12 inches (1 foot) is approx 30 centimeters.
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Your common counting numbers, or Reference Cardinal Numbers, for depth seen on most Dive Tables are:
Imperial US (feet) by 10's:
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
Now note the depth conversion factors above ("3/10" and "10/3") between the two number sequences. . .
So Depth in Meters multiplied by 10/3 gives Depth in Feet;
Feet multiplied by 3/10 gives Meters.
Example: 18m x (10/3) = 60ft; 60ft x (3/10) = 18m.
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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 x (3/2) x 10 = 3000psi ; (3000psi x 2/3) ÷ 10 = 200bar.
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Ambient Air Temperature Range in degrees Celsius that most of us are comfortable in is from 20 to 25 deg C. To convert to degrees Fahrenheit, just double the Celsius value and add 30 (a rough but fair approximation for this temperature range as well as for tolerable water temperatures in the appropriate exposure suit within, above and below this range). So for example 20 deg C is roughly 70 deg F.