A heave compensation apparatus and method for a winch or crane system, the
winch or crane system preferably for a vessel and including a lift wire
for attachment to a load. The apparatus includes a vessel motion
measurement device which may be in the form of a motion reference unit
for measuring the motion of the vessel, and a control device or computer
capable of receiving an output from the vessel motion measurement device
and controlling the winch or crane system according to the movement of
the vessel, so as to stabilise the load. The apparatus may further
optionally include one or more of a lift wire tension measuring device
for measuring the tension in the lift wire; a lift wire distance
measurement device which measures the length of lift wire that has been
paid out; and a load motion measurement device for measuring the motion
of the load.