Optical ray tracing permits realistic simulations of light images to be produced by calculating the intensity and color of each individual light ray that is projected into a predefined scene. This paper presents a similar technique for the simulation of sidescan sonar images of underwater environments that are generated by the use of acoustic signals. The inherent properties of light in air and sound in an underwater environment produce several fundamental differences between the two techniques, mainly as a result of the temporal display of the sonar images. This paper investigates these differences, presents the basic methodology of the sonar simulation model, and illustrates the techniques used to circumvent the time-based display problems. Finally, some results obtained using this technique are presented.