A gyrocompass's similar to a gyroscope. It's a compass that finds true north by using an (electrically powered) fast-spinning wheel and friction forces in order to exploit the rotation of the Earth. Gyrocompasses are widely used on ships. They've two main advantages over magnetic compasses: they find true north, for example, the direction of Earth's rotational axis, as opposed to magnetic north, they're far less susceptible to external magnetic fields, for example those created by ferrous met… (More on Gyrocompass)