The U.S. Navy's new Computer Supported Operator Training System simulates in a series of instructional games the operational environment of the Ships Inertial Navigation System, used as a precision source of navigation data aboard aircraft carriers and submarines. Designed for use at ashore schools for initial operator training and aboard ship for refresher training, the training system's digital computer simulates dynamic, realistic at-sea conditions. A unique Self-Instruction computer program module provides for automatic loading, sequencing, monitoring, and evaluating of games; computer control of time-compression permits twelve hours of ship patrol to be presented in one hour of instructional time. Thus the Computer Supported Training System effectively multiplies the availability of equipment for operational training while reducing operating hours of costly simulated equipment. No new hardware is required: the training system is made up of the inertial navigator's own dedicated digital computer and input-output devices along with special training computer tapes and instructional game workbooks.