In recent years the phenomenal growth in the number of research submersibles has given rise to the need for research into trainers for submersible pilots and scientific observers similar to those used by aviators in Link-type trainers. This paper presents the design approach being taken by the NAV-TRADEVCEN in building a device which will be used as a research tool for future trainers. The system which includes a vehicle that moves in a tank of water containing bathymetric models is described. Details of a sophisticated optical system which is used to scale the view realistically as seen through an underwater TV and an optical port are presented. How the vehicle is provided with 6 deg of freedom of motion and is navigated using simulated sonar guidance systems and other instrumentation standard on Alvin-type submersibles is discussed.