FYA Map Basics - Magnetic Declination Explained

When you learned how to set a compass bearing with us you will have noticed we talk about magnetic declination.  It sounds complicated, but it just isn't.  Here's why it's important, and how to deal with it:

The little needle on your compass points to the magnetic north pole.  That's all it does and it does it with amazing reliability.  The problem is that the north-south grid lines on your map point to grid north - which isn't in the same place.  The magnetic north pole actually sits somewhere to the north west of Greenland and it's gradually moving eastwards. 

In 2018/2019 in the UK this means that the direction that the compass needle points is, broadly speaking, between 0 and 3 degrees to the west of Grid North (the north that the grid lines on your map point towards). This varies depending on where you are in the country...  so check the map - it WILL tell you in margin.

So if you were to follow your compass needle to reach the geographical north pole, you would never get there.  Because of this, you need to adjust your compass bearing once you have set it, to account for this discrepancy.  The discrepancy is called "Magnetic Declination".

All you have to do to put this right, is to set your compass bearing (check how to do that right here) and then just twist the bezel of the compass a further 2 degrees in a clockwise direction.  That's it!  You're ready to follow an accurate compass bearing to your destination.  

You can check out our YouTube video right here:


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