AbstractThis paper describes a CAD facility for the design of automatic guidance and control strategies for an unmanned autonomous submersible. The facility utilises a three dimensional colour graphics display of the scene and vehicle trajectory, providing a man/ machine interface for the operator in addition to vehicle motion simulation with six degrees of freedom. A primary application envisaged for the CAD facility is in the design of scene analysis algorithms and the intelligent control system structure, for an autonomous submersible employing scanning sonar as its target sensor.