An improved motion compensator device that includes a compensated framework for various types of well intervention operations where a stable work area is required that is stationary to the sea bed and equipment in the annulus. The device is intended for use on offshore drilling vessels that are primarily either moored or dynamically positioned and therefore subject to the motions created by the sea. The device is designed to compensate for the vertical motion of the rig by means of two steel frame assemblies, pneumatic compensating cylinders, and a load and motion transfer apparatus.