The development of a Marine Engine Room Simulator system for training and research is described. Development objectives of the system are for both student training, research and development work. The system includes a distributed server/client architecture for 1 to 1, or 1 to many client simulation operation through OPC server, complete separation of visual elements from the controlling routines and the ability to work on the mathematical model independent of the controller and visual systems. A graphical user interface for the man-machine interface has been developed and the mathematical model has been updated. Various engine room operational situations can be simulated. The use of marine engine room simulator for training of sea going engineers and its competency for STCW-95 is discussed.