Natural Navigation - a beginning

Natural navigation is the ability to use nature to find your way rather than using a compass or another tool (such as GPS). It's a useful skill if your lost without any technology; but like all skills, requires practice to perfect and keep fresh. It’s a pretty big subject and I couldn’t cover it all in one post so there will be a series of posts about the subject. Its worth getting to grips with some basic concepts that will lay the groundwork for calculating direction without a compass. The first area I’m going to cover is navigating using the sun as this will set the foundations for the more complex night navigation. 

Firstly lets establish one certainty. The Earth and the moon are always lit by the sun, we don’t see the sun at night as the other half of the earth is lit and is blocking our view. So the position of you on the earth in relation to the sun will determine what you can see of both the sun and the moon.

So, let’s start with the position of the sun. The sun rises in the east and sets in the west  and the earth rotates once (360 degrees) every 24hrs (the sun only truly rises in the east and sets in the west on the spring and autumn equinoxes, but it’s good enough for some rough estimates). So based on this fact 360 degrees / 24 hours = 15 degrees of movement every hour. Knowing this, it means that the sun goes through a quarter of its movement every 6 hours.

So if we know where the sun is at a particular point we can work out from the time how many degrees the sun has gone through at a given time. The quick answer is that the Sun is due north at midnight, but why? We know the hottest part of the day is at midday when the sun is directly south of us, so 6 hours before that (1/4 of its cycle) its due east and just rising and 6 hours after its due west and setting. So roughly the sun rises in the east at 6am every day and sets at 6pm every day. Therefore this means its due North at midnight. The complexity to remember is to remove an hour on to your watch during British Summertime (when the clocks spring forward) or always work on GMT.

That’s all very interesting but how do we use it in practice? Well, if you know the time  (GMT) then by multiplying the number of hours after midnight by 15, you will get the degrees that the sun is at: so 9am is 135 degrees (9hrs x 15 =135 degrees). Another example? where is the sun at 4pm?  4pm =16:00 hrs or 16 hrs after midnight 16hrs x 15 degrees = 240 degrees.

So let’s check this theory. If your not familiar with a compass, see this post about compass parts: https://thecraftywoodsman.blogspot.com/2018/10/navigation-compass-parts.html. Firstly work out where you think the sun should be for the time of day. Take your compass and using the arrow on the base plate (the direction of travel arrow), point it in the direction of the sun (never look directly at the sun, you’ll damage your eyes, and don’t point the compass directly at the sun, you need to keep the compass flat). Next, turn the dial on the compass to align with the arrow in the middle of the dial (the orienteering arrow) with the North position of the needle on the compass. The bearing of the sun in now indicated by the index line on the dial. Did you remember to add an hour to your calculation in the summer?

So, what next? Well, you now know where the sun is in degrees, so you can work out the main cardinal points (N,S,E,W) and some basic directions and bearings knowing that the main cardinal compass points are set degrees off the bearing you calculated. i.e. North is at 0 degrees, South at 180 degrees. 

There is another way to use your watch (ideally not a digital watch, but you can draw the hands on paper if that’s all you have) that work well between 6am and 6pm. Point the hour hand at the sun and bisect the angle between the hour hand and the 12 on the watch dial (-1hr during BST) this is the red line in the diagram.  This will give you a north-south line with the imaginary line heading south. From this you calculate the other cardinal points.

But, let’s imagine you don’t have a watch so you don’t know the actual time, what now? You can use a thin straight stick and some patience. Ideally in a sunny area, place a thin straight stick in the ground and mark on the ground where the tip of the shadow ends. Wait a good length of time (the longer the better) and then mark the new position of the shadow end on the ground, ideally you do this over an hour either side of midday. If you place a line between the two marks you made on the ground, you will get an approximate east – west line and again, you can use this to calculate the cardinal compass points. If you have enough time and do this over noon, the shortest shadow will give you the North – South line, using an imaginary line between the stick and the closest point.

Now, get out there and practice.