Navigation without a compass

I mentioned Marvin Creamer in an earlier post -- he did a circumnavigation without any instruments, i.e., without a gps, compass, sextant, or even a watch. I haven't ordered, or read, his book yet, but over the last few days I've been trying to re-hone my land navigation skills while recovering from poison ivy.

One of the things I've been trying to get better at is estimating distances. NATO forces use the mils system, 6400 mils to a circle, to estimate distances for artillery spotting. Basically, it's 1 meter will be 1 mil at 1,000 meters (you can use yards or feet too, but they normally use meters -- a click on military maps is a grid square that's 1,000 meters on each side). Using this formula, a circle is can be divided into about 6,283 mils, however, NATO rounds that to 6,400 for simplicity.

With this formula, you can estimate the distance (d) to a target of know size (s) by estimating the mils and using the formula: (s/mils) * 1,000 = d, e.g., if you assume a man is 2 meters tall (a little over 6'), then he's 2,000 meters away if his height is 1 mil. If his height is 2 mils, he's only 1,000 meters away, and so on. Maps, and more importantly for me, charts, normally list the height of important landmarks, e.g., lighthouses, so you can plug those values into this formula and quickly figure out where you are vis-a-vis some known point.

Figuring out how many mils is also easy. The rule of thumb is that the width of one of more fingers held out in front of you at arms length will represent a certain number of mils. The standard measures are: index finger - 30; index + middle finger - 70; index + middle + ring finger - 100; and so on. I've measured my fingers and found them to differ slightly, but in general, these will give you results that are close enough. (my fingers might be a little off due to the poison ivy, so I'll recalibrate them again later)

Another thing that I recently discovered was that you can use the crescent moon to find South in the Northern hemisphere -- not sure about the Southern hemisphere. Just extend the line made by the tips of the crescent to the horizon, and that's South. I think the accuracy depends on your latitude, but I'm not sure what that change is. I noticed that it was pretty close last night, so I'll try to calibrate it for my current latitude, ~ 41.5 degrees N, this evening. I'm not sure if Creamer mentions this in his book, but hopefully I'll get a chance to read it soon.

Poison ivy watch:

It's much better today, but I still haven't started doing any real work. The original patches seem to be going away, but some of the ones I got later are still in full bloom.