Patent ID: 8265811

Claim:
A method of actively compensating heave of a vessel to which a load is attached, there being a connection device connecting said load to said vessel, which method comprises the steps of: (a) measuring with a measurement device the heave of said vessel and outputting a heave signal representative thereof, which heave signal comprises a velocity signal representing velocity of said vessel in response to said heave; (b) using said heave signal to compensate for said heave by moving said connection device relative to said vessel as a function of said heave signal, whereby movement of said load due to said heave is reduced; said heave signal comprising errors induced by said measurement device whereby accuracy of said compensation is reduced, characterised by the steps of: (c) processing said heave signal by determining a velocity correction (vG) and adjusting said velocity signal by said velocity correction so as to reduce said errors and outputting an adjusted heave signal; and (d) using said adjusted heave signal to move said connection device to compensate for said heave.