Realism in presentation of visual and aural displays is the key to effective antisubmarine warfare (ASW) training. Early ASW trainers were forced to make compromises in realism and to make extensive use of operational equipment to provide adequate training. The generation of ASW trainers currently being procured offers vast improvement in display realism by making use of the explosive growth in computer technology and high-resolution graphics systems. Future trainers promise table-top, part-task, trainers to provide instruction at the unit level and operator and team tactics trainers with the realism of the operational equipment without the associated cost. The high cost of operational equipment makes the use of stimulation prohibitively expensive for large tactical team trainers. Team tactics trainers are using simulation of the sonar displays on commercial graphics systems. Commercial graphics systems are also being used in the development of low-cost table-top trainers. Research is contributing to future trainers that will close the gap between the simulator and the stimulation of operational equipment, with look-alike consoles that will provide both the appearance and the features of the operational equipment. This paper not only describes the development of ASW trainers from the earliest concepts, but also presents current research leading to significant advances in the realism of simulated ASW displays.