US Patent 7152547 Seismic vessel having motion-stabilized helicopter landing platform

A helipad motion compensation system for a vessel includes at least one controllable length actuator operatively coupled between the helipad and the vessel. The system also includes an attitude sensor disposed on at least one of the helipad and the vessel. The sensor produces signals corresponding to change in attitude of the helipad. A controller is in operative communication with the sensor and is arranged to operate the at least one actuator. The actuator is operable to substantially maintain an attitude of the helipad to compensate for motion of the vessel.