Basic Navigation Lesson 1 ACP32 Vol2

Basic Nav. By the end of this lecture you should know: Some ways to find North How to set your map The different “Norths”

Finding North The Pole Star This star indicates North in the Northern hemisphere.

Finding North Shadow Method Use the shadow cast by a stick

Finding North Wristwatch Method Hold the watch flat Point the hour hand at the sun. Clockwise between the hour hand and 12 is North. (In BST use 1 instead of 12)

Setting the Map This is done to easily relate features on the map to the physical environment. Find a common feature such as a waterway, road, path or geographical feature on both the map and the real world. Turn your map until the features line up.

The “Norths” There are three “Norths” 1, Magnetic North – Compass 2, Grid North – Map 3, True North – Earth (the real one)

The “Norths” As seen on OS maps

The “Norths” Variance The Magnetic North Pole does not coincide with True North. It is approximately 5 degrees to the west and moves a little every year. The details of variances are on every OS map in the margin. The GMA Grid Magnetic Angle. This is the difference between north on your map and north on your compass. Why do you need to know this? Answer: So the compass can be “calibrated” for use with the map.