The aim of this thesis is to develop a simulation tool, The 3-D Forward-Look Sonar Simulation Model (3-D-FLSSM), for the 3-D Forward Look Sonar or equivalent that provides insight to the defining characteristics of the sonar system that affect the image quality and the data processing. The simulator includes a representation of the acoustic environment, which incorporates a flat seafloor and spherical target, both of which are assumed to a have small-scale roughness (much less than the acoustic wavelength) associated with them. The backscatter from the target and the seafloor are calculated using the Rayleigh-Rice approximation implementing Kuo's backscattering cross section. The simulator is capable of modeling targets of various shapes and sizes. The 3-D-FLSSM assumes a plane wave approximation and a constant sound velocity throughout the water column. The final product is a simulation tool with a focus on shallow water littoral acoustics, which can be used to define the sonar hardware and processing software necessary to meet various operational requirements.