Why is your map covered in little blue squares?

Have you ever looked at an OS map and wondered why the entire country has been chopped up into a giant grid? Those little blue squares are part of the British National Grid and they're the foundation of one of the most useful skills we have in navigation - being able to describe exactly where we are.

The system divides Great Britain into progressively smaller areas, allowing us to turn a position on the landscape into a grid reference.

A four-figure grid reference identifies a 1 km square.

A six-figure grid reference narrows that down to a 100 m square.

And remember the golden rule: along the corridor, then up the stairs. Eastings first. Northings second.

Why is this so important?

Because a grid reference can help you plan a route, communicate your location to somebody else and, importantly, give emergency services a much more accurate idea of where you are if something goes wrong.

So next time you unfold your map, take a second look at those blue lines. They're not just squares on a piece of paper. They're a language for describing exactly where you are in the landscape.

Understanding the WHY behind the skills.