The sun is slowly rising and the birds begin to chirp. The day has begun and time passes by. In a survival situation, time is of the essence. In the summer, you want to set up camp about 2 hours before sunset and in the winter, you’ll need about 4 hours. This is because you’ll need time to gather the necessary supplies for a comfortable night. If you don’t have a watch, your sundial compass will help. When using a sundial, you’ll need to locate North. This is where it gets tricky because there are two Norths: Magnetic and True.
True North: The geographic pole where all meridian lines meet. Every map’s North is directly above. Sadly, an explorer’s true north isn't at the identical point as the one on his or her map, because the direction of one’s compass points to its magnetic north.
Magnetic North: Think of the planet as a large magnet (which it is). Now, remember back to when you were a kid in science class and the teacher passed around bar magnets. The Earth’s magnetic fields act the same way. The only difference is that our planet’s field is roughly at an eleven-degree axis. As a result of this, magnetic north is different than true north. The shift in our planet happens because of our molten core. Since the core is always moving, the magnetic field changes slightly. When one reads a compass, the needle is affected by this phenomenon. The diagram below shows the magnetic lines for the United States. Depending on the area one is in, the compass will position itself to that magnetic line.
As you can see, depending on your location, the compass will have a big difference between magnetic north and true north. That gap between the two is called declination and is shown in the diagram by directional degrees.