The Metric Rant

It’s time to change. Change to Metric.

People are creatures of comfort, but when comfort means more work, less accuracy and less ability to interact or integrate on a truly international scale, it ceases to be a comfort and becomes a liability. Thanks to the last conservative government in Canada, metrication stalled and fell to the wayside, much to our detriment. While felt at many levels in Canada, the area I’m specifically referring to is the area of diving, both recreational and occupational/commercial. Where the rest of the world has begun to forge ahead, we have fallen behind and stubbornly refuse to change.

There are many reasons people give as to why they dive imperial. Some examples are: “It’s how I learned.”, “It’s the standard.”, “The shops only sell imperial stuff anyways.”, or my favourites: “It’s more accurate.”, “It’s what I’m comfortable with.” and “It’s the industry standard.”. Lets look at these one by one:

  • “It’s how I learned.”: We all learn things in life that we later have to change, modify or in extreme cases, unlearn. Just because you learned something one way doesn’t mean you can’t learn to do it another way.
  • “It’s the standard.”: No, actually, in a purely numbers based game, Système International d’Unités is the standard, with only a handful of places using a purely imperial based system.
  • “The shops only sell imperial stuff anyways.”: Ask and ye shall receive. The reason shops don’t carry a large amount of metric gauges and so on is because no one thinks to ask for them. There’s no difference in price, and the more people who ask for it, the more often you’ll see it stocked.
  • “It’s more accurate.”: The standard of measure for depth in imperial is feet. The metric system uses metres… and fractions of 10 thereof on your computer. 10cm is closer to an actual depth than the 30.4cm/12” area of a foot. In addition, given that almost all dive physics need ATA (atmospheres absolute), and absolute temperature (i.e.: the Kelvin scale) the metric system allows for far more accurate calculations.
  • “It’s what I’m comfortable with.”: This excuse and its variations get paraded out for everything from why people don’t like using condoms to why they don’t wear seat belts in cars. This one also has the romantic side to it; that being that a person can hold a cup, or see a foot in their day to day. Unfortunately, this visualization has nothing to do with proper measurements, as feet are seldom exactly 12 inches in length, and cups come in a variety of sizes.
  • “It’s the industry standard.”: This one is a rough customer. Why? Because of the intransigent nature of some professionals and groups, who will fight tooth and nail not to have to change anything because of (wrongly) perceived ideas that it won’t work, will cost too much money, or any of the excuses I outlined above. This becomes more of an issue because they are the ones who teach the newcomers into industry the ropes, and pass on their own biases and thoughts, prolonging the conversion process if not derailing it completely.

Lets talk about some of the benefits of using the metric system in the diving world. For one, most of the world dives metric. The only areas where you commonly encounter imperial measurements are the United States, Burma and Liberia, where the imperial system is in full usage; and in areas heavily frequented by american tourists. Everywhere else is metric. Dive physics and equations become vastly easier to calculate and more accurate when the metric system is used. An added bonus to the last point is the application becomes easier as well, as dive computers can measure in decimetres (10’s of centimetres or 1/10’s of a metre).

Many say the conversion would be too harmful and hurtful a process, with the older divers being left out in the cold and younger divers being clueless as to what older divers are talking about. I disagree completely. Given that dive tables are available for the most part with metric and imperial measurements, it’s very easy for older divers to start writing things in metric; and to begin associating depths with metres. It’s even easier if you use a dive computer! Younger divers simply need to start metric, or, like me, change over early in their diving careers before they become hidebound to an obsolete system. What many say here is that the imperial system is more “intuitive” for diving. I disagree. We’re talking about numbers here, and one set of numbers gives more accurate results and more accurate measurements using a simpler system. The term intuitive here is used as an indication of comfort and familiarity; two things one gets by practicing with and using a system. Conversion can be awkward, slow and even frustrating, but so is being the only imperial diver on the boat and having to have the dive brief explained to you after everyone else because you don’t have an “intuitive” grasp of 30m max depth.

As I said before; intransigence is the biggest issue we face in Canada as metric divers. Our large neighbour to the south still uses its own variant of the imperial system, and for some Canadians born and educated before the mid seventies, the metric system is still something of an enemy. We still describe height and weight by imperial measurement, even though our drivers licenses are metric. Precisely because we trade heavily with the last major imperial system using nation on the planet, some would have us regress or stagnate in the name of appeasing a trade partner, who makes metric gauges and dive tables for sale everywhere else in the world. The USA’s diving community doesn’t care if we’re diving imperial or metric; neither do their dive equipment manufacturers. So why not dive metric?

As I said before, it was the actions of our government in Canada in the 1980’s that stalled our conversion process. This was followed by divers trained in the imperial system stubbornly sticking to it and passing their own biases onto new divers without regard for the future or the ability to interact with the larger world of diving. Gauges, computers and dive tables are all available in metric measurements. The arguments against the metric system are empty of real content or substance, and are largely based are personal discomfort with having to spend a bit of time learning a new system. When I read about diving in cool, unusual spots, I see them using the metric system. When I look at government tide charts and marine maps, vital to planning scientific dives, I see depths listed in metres. When I hit the water in Bali, it’s 21˚C, and at home in British Columbia, it’s 6˚C. When it’s time for using Universal Gas Law, or figuring out ATA and ATM, the metric system is faster and more accurate both on paper and in potential application. Scientific measurements of marine life are taken in centimetres or meters, transect lines are by metre and quadrats are typically 50cm x 50cm or 1m x 1m. It’s time for the weird hodgepodge of imperial/metric to pass, and for us as Canadian divers to accept the metric system wholesale and expand our horizons.

I’m a metric diver, and I’m Canadian.

About the author

Graeme is a professional diver, qualified as a PADI and SDI Divemaster, DCBC 40m Unrestricted Commercial Scuba Diver, 30m Restricted Surface Supply diver, and CAUS Scientific Diver Lv.2. Graeme has an Associate Degree of Arts in Environmental Studies, where he focused on archaeology and physical geography, and an Advanced GIS certificate.