The present invention relates to a heave compensator comprising- a main hydraulic cylinder (1) comprising a first connection device (5) located at an upper end of the main hydraulic cylinder and a first piston (2) having a piston rod (6), where the interior of the main hydraulic cylinder (1) is divided by the first piston (2) into an upper first chamber (3) and a lower second chamber (4) filled with hydraulic liquid, and where the piston rod (6) has a second connection device (7) located at a lower end of the piston rod (6),- a lifting accumulator (10) comprising a second piston (11) dividing the interior of the lifting accumulator (10) into a third chamber (12) filled with gas and a fourth chamber (13) filled with hydraulic liquid, wherein the fourth chamber (13) is fluidly connected to the second chamber (4) by a first liquid conduit (30) having a first actuator controlled valve (31) regulating the flow of hydraulic liquid in the first liquid conduit (30),- a lowering accumulator (20) comprising a third piston (21) dividing the interior of the lowering accumulator (20) into a fifth chamber (22) filled with gas and a sixth chamber (23) filled with hydraulic liquid, wherein the sixth chamber (23) is fluidly connected to the second chamber (4) by a second liquid conduit (32) having a second actuator controlled valve (33) regulating the flow of hydraulic liquid in the second conduit (32),- the sixth chamber (23) is fluidly connected to the fourth chamber (13) by a third hydraulic liquid conduit (40) comprising an actuator controlled pump (41) unidirectionally regulating the flow of hydraulic liquid from the sixth chamber (23) to the fourth chamber (13), andin that the heave compensator further comprises:- a sensor kit comprising a motion sensing unit (51) registering the vertical movements of the main hydraulic cylinder (1),- a logical controller unit (50) comprising a processor loaded with a Valve Regulation Module containing logic commands which when executed controls and regulates the actuator of the first actuator controlled valve (31), the actuator of the second actuator controlled valve (33), and the actuator of the actuator controlled pump (41), and- signal transferring lines (52) electronically connecting the logic controller unit (50) to the motion sensing unit (51) of the sensor kit, the actuators of the first (31) and the second (32) actuator controlled valves, and the actuator of the actuator controlled pump (41).