As I was writing my last post, it occurred to me that I always quote distances in miles and ascents/descents in metres. You may be wondering why ?
I’m part of the ’70s generation that was intensively taught metric at school, whilst in the real world it still wasn’t really used at all. So we were “made aware” of imperial too, so that what we learnt would actually be of practical use. As a result, I grew up with conversions between the two, and still have my old inherited book of mathematical tables with them all in. And I still use it. Especially when I need to know the formula for the motion of a pendulum.
I’ve tried sticking to either metric or imperial for the numerical side of my outdoor activities, but it doesn’t work for me since measuring longer distances in miles is so ingrained, whilst at the same time metres for height gain fits in the rules of thumb that I’ve developed along the way.
So I tend to use:
- Miles for longish distances (unless I want to make it sound more impressive by using kilometres)
- Metres for micro-navigation. We’ve all done the 100m in school sports so it’s a natural measure.
- Metres for ascent – a metre of ascent is meaningful, whereas 1 foot is within the margin of error of my altimeter, and so useless as a measure of height gain. I can also estimate heights in metres a lot more easily than feet.
It’s not a problem to mix and match these as the main interaction is for me to estimate walk lengths and times by converting the height gain to equivalent distance (what I call Flat Equivalent Distance, or FED for short). In this 150m of ascent equates roughly to a mile of flat walking. And I find that my climbs seem naturally to fit in with the blocks of 150m measure – 450m is about a day’s walk on my local stretch of the North Downs Way, 600m is a mountain height (ok, 610m, but it’s close enough), 750m is about the average daily climb I do on a hill-walking trip, 900m is often a big day.
Now being French, my sports watch insists that I use either metric or imperial, but at least it gives me the choice. So I’m faced with choosing distance in miles and ascent in feet, or distance in km and ascent in metres. I’ve gone with metric, as it’s a lot easier and more accurate to convert a distance in km to miles, because you do a lot less of them than metres/feet climbed. But when I map routes in Anquet, I have flexibility and so have distance in miles and ascent/descent in metres.
It’s weird, you may think, but it works for me.