– Offshore cranes and other equipment doing subsea work are provided with AHC systems to ensure presicion in high sea states and extreme weather conditions. The essential function of AHC technology is the ability to land and retrieve subsea installations to and from the seabed with precision and accuracy, while minimising the impact caused by the motion of the vessel. The major principle of AHC technology is based on advanced motion sensors that measure the vessel’s heave, pitch and roll and calculate resulting geometrical estimate of heave motion of the point where a lifting wire exits the vessel. AHC uses complex electro-hydraulic PLC controlled systems to control the movement of the lift wire so that the motion introduced by the crane-tip is damped as much as possible. It enables modern subsea vessels to continue working with loads near the seabed under increasingly adverse weather conditions.