# how does navigation with a compass work?

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Wouldn’t setting and facing a compass to 20 degrees West, mean the needle points 20 degrees east (on the compass face)?

In: Technology

You orient the needle to be on the N of the compass. Now you orient yourself to be pointing across the compass in the direction you want to go. Now walk.

There are 3 north’s. Magnetic, true and grid north. So to use a compass, you have to know the declamation angle, do some quick add or subtraction maths and now your north on your map is the same north on a compass.

The declamation angle is printed on the map and depends on where your at

You don’t point the compass with the needle. So if you want to go 20 degrees to the west, you would be going west by west north west. The face of the dial is 360 degrees starting at true north and rotating clockwise. (True south is 180 degrees) so to point 20 degrees west you would be pointing at the 340 degree mark.

So you would pull out your compass, let it find north and then rotate yourself till you were facing 340 degrees. Some compasses have a reticle you could then look through on a flat plane. You would either use that or simply look up and find a landmark (tree, ridge, boulder, etc.) And walk to it. Once you get to it you get out the compass and remeasure.

This is of course only for land navigation. At sea you would need a dedicated navigator to stay on true direction or could use a sextant to use sun, moon and stars as landmarks.

The needle always points north. Rotate your compass to line up the N under the needle. Walk in your desired direction. If you know where you are and you have a map, you can lay out your map on the ground so that north on the map and north in real life are the same direction. Pick a destination and figure out what compass heading you need to walk to get there. Count your steps for distance.

1.Take a map and point the north on the map to the north that compass shows.

2.Find out where you are by landmarks.

3. Figure out where you want to go and point yourself in that direction.

4. Take a map with you and keep walking in the same direction, look at the compass every now and then to keep direction.

Repeat the process wherever you don’t know where to go next.