Abstract: The present invention provides three different algorithms, namely, the “divide and conquer” algorithm, the “Hiddensee compensation” algorithm, and the “impulse response” algorithm. Any one of these three inventive algorithms may be made a part of an overall degaussing algorithm for a marine vessel. Each corrective algorithm, by itself, compensates for deviation of the vessel's induced signature from direct, linear proportionality to the ambient magnetic field. This deviation is associated with the dependency of a marine vessel's magnetic signature on the frequency at which the vessel rolls in the water. Practice of inventive compensation tends to be increasingly called for with increasing magnetic character of the vessel.