The safety of submarines requires that they be designed acoustically quiet to avoid detection. One method to reduce acoustic emission is to surround the hull with a viscoelastic layer. In order to access the effectiveness of these viscoelastic layers, it is necessary to determine the three-dimensional (3-d) surface complex impedance and acoustic loss as a function of frequency for a steady state harmonic input. This project will provide for the accurate assessment of the effectiveness of these viscoelastic layers by developing an efficient, modular, user-friendly, dedicated 3-d finite element code that is capable of determining the complex surface impedence as a function of the steady state driving frequency and accurate modeling techniques for these unique geometries.