This rig was developed to test sensors for the undersea pipe laying industry. A heavy duty aluminium framework houses a vertical linear actuator and a 2 axis rotary positioner using direct drive servo motors. The vertical actuator has a sinusoidal move profile designed to simulate different conditions at sea. The rotary axes are used to test the sensors onboard positional feedback to resolutions of 1 million counts per revolution. The sensor and motion control position feedback is linked to a control PC which produces a graph of results which forms part of the customers QA documentation.