The operation of the magnetic compass is influenced by the lines of the earth's magnetic field and the compass' directive element would adopt the direction of the lines i.e. align with the magnetic meridian, if it were not for the impact of the deviating magnetic field, consequential to the magnetism present within the iron structures of the ship. Gyro compass is a controlled and damped gyroscope that only works being supplied electrical energy. Due to both the rotor's angular momentum and precession triggered by the tilt of the axis of rotation, utilizing gravity and being affected by the rotation of the earth, it tends to seek the true meridian; the rotation axis of the rotor, though, needs to settle in the meridian, which is attained through damping of oscillations. With regard to the fact that the compasses operate in a dissimilar way and that they are subject to different factors, the character of operational errors of each of the compasses proves to be entirely distinct. And since the factors are many, various types of errors arise, of which each needs to be acknowledged and addressed to, when possible and practicable, by means of the proper method.