Friday, May 13, 2011
Most people avoid math whenever possible. I was one of those kids in school that actually liked math. It was easy for me, it made sense, it didn't involve conjugating verbs. With calculators, computers, and the general dumbing down of society, most people don't do much math in their heads anymore. Sailing is no different, there are electronic devices to do most of the math for us. We have a chartplotter on the boat, a small video screen that shows nautical charts, and with its built-in GPS can show our position on these charts. By moving the cursor to the spot I choose for a destination, it will show me how many miles away I am. It can also tell me at my current rate of travel how long it will take to get there, and when my attention wanders watching an eagle through the binoculars, it tells me how much time I've just added to the trip by wandering off in some random direction. Even though I use this function regularly, I find that I am also doing the calculations in my head, checking to make sure they are right, because you really can't trust those electronic thingies. It's a struggle some times to find reasons to do math, so I purposely make up reasons. Water depth is a perfect example. The charts on our electronic chartplotter are set to read water depth in feet. My subconscious seems to work in feet so glancing at the chart it's easiest to assess danger that way. Most of the paper charts we carry have the depths in fathoms. Converting 6 feet for each fathom is pretty simple. Our depth sounder on the boat is set to meters. We bought the boat in Canada and the depth sounder was set to meters, and we've never bothered to change it. In fact, when we replaced the chain for our anchor we purposely marked the lengths in meters to match the depth sounder. It's not much, but the conversion from feet to meters to fathoms, back and forth, keeps my math muscles from going away completely.