Current methods of producing clean water are not capable of meeting growing demands. One method of producing clean water is through a process called desalination, which is the process of removing salt and other minerals from seawater. However, traditional desalination methods can be energy-intensive and generate significant amounts of waste. To help address these issues, a hybrid wave-to-water desalination system that combines reverse osmosis (RO) with supercritical water desalination (SCWD) can produce freshwater from seawater. SCWD treats the brine produced by RO, while RO produces freshwater at a lower energy cost. The system utilizes an oscillating surge wave energy converter (OSWEC) to harness the energy of ocean waves to directly pressurize the seawater feeding into the RO system. Using ocean waves as an energy source makes the system renewable and reduces the carbon footprint of the desalination process. This thesis presents the development of a simulation for a small-scale zero-waste desalination system powered by off-grid renewable energy. The model of the system was developed using MATLAB Simulink along with WEC-Sim. A sensitivity analysis was performed on the model to determine the optimal configuration of key system parameters. The sensitivity analysis was conducted using an irregular wave pattern with a significant wave height of 0.117 m and a period of 1.68 s. The parameters investigated in the sensitivity analysis were the system's power take-off (PTO) volumetric displacement, accumulator size, and RO membrane type. The results of the sensitivity analysis showed that the optimized system was the one that used an SW30HR-380 RO membrane, a PTO volumetric displacement of 1975 cm^3/rad, and a 10-gallon accumulator. The average water production rate for the optimized system was 32.644 gpm.