Written by 3:10 pm Wilderness Navigation Masters

16) Forward bearing and back bearing

(Last Updated On: June 7, 2021)

Hello and welcome to this lesson of the online course Wilderness Navigation Masters, where you will learn about the forward bearing and the back bearing.

What is bearing?

This term of the bearing may seem meaningless to you the first time you hear it, but it’s not the case, because, as we’ve seen before, a bearing is just the angle between two references.

  • For example, between Geographical north and a point that you want to arrive at.

Because a bearing is an angle, we say “a bearing of 90°” or “a bearing of 180°”, and he can go up to 360°.

You may ask me, yes, I understand what you say, but how can that help me in my wilderness navigation?

Totally understandable, a bearing is what helps you make CORRECT turns in the wilderness. Because when you know your position on your map, and you want to go to a new position that you see also on your map, all you have to know is the angle or the bearing between one of the norths and this point on the map.

And if you still don’t see the importance of a bearing, just wait till the next module when we will use both the topographic map and a compass at the same time.

Expected mistakes:

Let’s see this illustration to talk about an expected mistake that you may not know about.

If we are at the red cross, and there is a landmark here that we want to go to, let’s say a water well, this direction with the angle of 25°, between the geographic north and the water well is the bearing that, if we follow, we will arrive at the water well.

The first expected mistake is that people think that if we move in the same line of the geographic north, we will still have the same bearing …  which is not true. If you are at the red cross, the bearing to the water will be 45°.

If we move to the red cross to the opposite of the first place, the second expected mistake that may happen to you is thinking that the bearing to the water well is 25°, which is not true.

Because a bearing is always measured clockwise, here, the bearing to the water well is 335°.

 

How to take a bearing in the wilderness (skip to2:19):

Now that you are a little bit familiar with what is a bearing, let’s see how can you measure it when you are in the wilderness.

Show video transcript
  • To measure the bearing of this place right. All you have to do is to aim at it with the direction of travel arrow.
  • Now, turn the liquid capsule till the red is in the shed.
  • Now read the graduation on the liquid capsule at the intersection with the direction of travel arrow.
  • In this case, it’s a bearing of 257°.

I feel that after this example, you started getting confidence in yourself, and this is a good thing.

 

Back bearing:

Now, before I jump to this lesson quiz, I want to just add a little new term which is “Back bearing”.

Yes, “Back bearing”. Because what you’ve just learned was the forward bearing.

Back bearing is what helps us to determine the direction to our original position from a landmark.

We can measure a back bearing just from a forward bearing. we only add or subtract 180°.

If you’re forward bearing measure less than 180°, to get the back bearing you have to add 180°, and when the forward bearing measure more than 180°, to measure the back bearing you have to subtract 180°.

If you wonder why 180°? why can’t we add or subtract 90° or 200°, I have a good explanation for you.

Skip to 4:04

 

Show video transcript
  • If we go back to our previous example of the water well, the back bearing is the angle from our water well to our original position.
  • If I draw this line, this angle will be the exact one as our forward bearing, and this angle is 180°.
  • So this angle of the back bearing is 180° plus the forward bearing.
  • And without measuring it, I can know, that it’s a 200° angle. And I encourage you to check it yourself using a protractor.
  • Now let’s go back to the field, and see how can we shoot a back bearing.
  • Measuring a back bearing is similar to the forward bearing.
  • You aim at your destination.
  • Instead of turning the liquid capsule to the red area in the shed, you keep turning it till the opposite direction of the magnetic needle is in the shed.
  • And like you see, the back azimuth is X°.

 

That’s all for the forward bearing and the back bearing, now to make sure that you remember what you’ve just seen, let’s see the first quiz.

 

Question #1

If we take the red cross sign as your position, the bearing of 115° is

  1. a forward bearing
  2. a back bearing?

 

SHOW ANSWER

The correct answer is forward bearing.

Question #2

The same thing for your position, the azimuth of 45° is :

  • A) a back bearing to your position
  • B) the forward bearing to the water well?

 

SHOW ANSWER

For question #2, The same thing for your position, the bearing of 45° is a back bearing to your position or it’s the forward bearing to the water well?

The correct answer is “A”, a back bearing to your position because the forward bearing to the water well is this angle.

That’s all for this lesson, like always if you have a question, do not forget to put it in the comments section below.

Thank you again and see you in the next lesson.

Last modified: June 7, 2021

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