Roger Bailey wrote: > I recommend the old Air Force Survival Manual (AFM 64-5). > ... > Find your location (Latitude and longitude) and > direction (north) using the shadow of a stick. Make a sextant from fishing > line or parachute cord. Find your latitude from the length of daylight, or > by measuring solar and Polaris altitudes with a Weems Plotter. A > fascinating book; > ... > On my backcountry explorations, my survival kit does not contain a > parachute with all that useful cordage and fabric. My weapons are limited > to a Swiss army knife and a big stick. Most of the advice in the manual is > therefore not applicable. > > Accuracy is limited with such navigational techniques. For > example it would > be difficult to determine whether you came down in Kosovo, Macedonia or > Serbia. This could be important!
I'm willing to (brashly) bet there was never a pilot who ever used these techniques or even took them seriously. Knowing your latitude and longitude without a map is useless, and if you have a map it is a lot easier and quicker to find your location from the terrain. If you can't find your location from the terrain because everything looks alike, an estimate of your latitude and longitude will not help much either. Mountains or rolling hills, possibly even forests, are likely to make a measurement of the length of the day too inexact to be useful. The only thing that is truly useful is finding directions, but then you should pack a compass, not a sextant. (That isn't to say none of this is "fascinating".) I do think being able to look at the sun and estimate directions could be useful (in case you forgot to pack a compass, shame on you!). On my list of things I would like to do and know how to go about but haven't found the time is to investigate telling directions from the moon. I read an article in the magazine of the German Alpine Club a few years ago on this topic and found it incredible. With a Ph.D. in physics I think I can figure out how many hours to add or subtract in which direction to convert moon position to sun position and then to direction, but I bet very few people dumb enough to get lost at night without a compass can. But even without a watch, if you see the moon rising, you know that's east. And if the shadow is oriented straight up and down, then the moon is in the south. You don't need to know much more than that to find the nearest road. --Art Carlson
