Compass principle - All compasses include a magnetized needle that orients itself to the magnetic fields in the Earth

Understanding magnetic needle -

The red needle in the magnet always points the North direction and the white points to the south direction. Turning towards the north, the right side indicates the east direction. Thus we can find out directions based on the magnetic compass.

Mapping aids -

Generally, the sailors do have a map with them with the departure, arrival and the key points on the way marked on the map.

Placing the map on a flat surface and placing the compass on the map helps them to get a more accurate reading.

Direction and angle -

• Turn the degree dial until the orienting arrow lines up with the magnetic arrow, pointing towards the North, and then find the general direction you are facing by looking at the direction of travel arrow. If the direction of travel arrow is between the S and the E, say, you are facing South east.
• Find where the direction of travel arrow intersects with the degree dial. To take a more accurate reading, look closely at the degree markers on the compass. If it intersects at 22, you are facing 22 degrees South east.

Before technological advances like GPS and radar came along, peoples lives depended on navigating accurately by compass alone. That is why ship s compasses (sometimes called mariners compasses) were much more sophisticated than the ones people typically used on land. In a modern ships, much more advanced technology is being used, now a days.