Now I realize how out of fashion the lowly and ancient magnetic compass
is in light of the New Dispensation of GPS
, but I still like to call myself Hornblower and refer to the little Plastimo compass
in the cockpit
. In fact, I use it to, you know, navigate.
On my local chart, the compass rose says, as they do, something along the lines of "10 degree W deviation (1994)". That means if I read 90 degrees on the compass, it's actually 80 degrees T. It also suggests that the last time someone was around here with a Great Big Azimuth Compass was going on 20 years ago.
Unfortunately, the stately and predictable movements of our Magnetic North Pole are becoming...well, skittish, and the rate of deviation (also marked on most charts) is probably undervalued.
Does this affect the average sailor? No. When it hits 11 deg. W in my home waters is unlikely to affect my helming or pilotage as I can't steer better than a 5 deg. wobble most of the time. Nor would I want to.
But I have found it interesting that there are starting to be real-world effects due to the Wandering Pole:
Tampa airport runways renumbered due to magnetic north movement
"The primary runway at the airport
is designated 18R/36L, which means the runway is aligned along 180 degrees from north (that is, due south) when approached from the north and 360 degrees from north when approached from the south. Now the Federal Aviation Administration
(FAA) has requested the designation be changed to 19R/1L to account for the movement of the magnetic north pole
I point this out as a navigational curiosity and as a small token that the Earth doesn't really care what is printed on our charts