A wave energy converter (WEC) system has the potential to convert the wave energy resource directly into the high-pressure flow that is needed by the desalination system to pump saltwater to the reverse-osmosis membrane and provide the required pressure level to generate freshwater and or green hydrogen. In this study, a wave-to-water numerical model was developed to investigate the potential use of a wave-powered desalination system (WPDS) for water production and the production of green hydrogen. The model was developed by coupling a time-domain radiation-and-diffraction method-based numerical tool (WEC-Sim) for predicting the hydrodynamic performance of WECs with a solution-diffusion model that was used to simulate the reverse-osmosis (RO) process. The objective of this research is to evaluate the WPDS dynamics and the overall efficiency of the system. To evaluate the feasibility of the WPDS, the wave-to-water numerical model was applied to simulate a desalination system that used an oscillating surge WEC device to pressurize incoming seawater through the system. The green hydrogen production model is a completely closed system that uses the hydraulic cylinders to turn a hydraulic motor that turns a wind based permanent magnet 5 -10 Mega Watt generator which then uses the electricity using electrolysis to break the hydrogen oxygen bonds creating green hydrogen. The hydrodynamics WEC-Sim simulation results for the oscillating surge WEC device were validated against existing experimental data. The RO simulation was verified by comparing the results to those from the Dow Chemical Company’s reverse osmosis system analysis (ROSA) model, which has been widely used to design and simulate RO systems. The wave-to-water model was then used to analyze the WPDS under a range of wave conditions and for a two-WECs-coupled RO system to evaluate the influence of pressure and flow rate fluctuation on the WPDS performance. The results clearly demonstrated that the limitations imposed by the standard model resulting in instantaneous energy fluctuation from waves was eliminated as a significant influence on the responding hydraulic pressure and flow rate, as well as the recovery ratio and, ultimately, the water-production quality and the potential energy output. The standard model was broken with the staging of seawater in the primary impound areas with precise intervals where the seawater was released to flow into the sub-impound areas. The model is based on the conversion of kinetic to potential and back to kinetic energy. KPK represents a seismic shift in the standard model. The time interval limitation imposed by the 9 second cycle time between wave crests. It demonstrated that it is possible to eliminate the hydraulic fluctuation for different sea states while maintaining a certain level of freshwater and green hydrogen production. The model clearly demonstrates that a WEC array that produces fresh water and green hydrogen can be a viable, near-term, and long-term solution to the nation’s increasing demand for fresh water and a sustainable source of clean sustainable energy to power transportation, homes and industry. A study on the dynamic impact of hydraulic fluctuation on the WPDS performance and potential options to reduce the fluctuation and their trade-offs is also presented with historical data from two centuries of data collection of sea states identifying standard wave height and wave intervals. In short, the marriage of these two technologies represents a mutually sustainable synergy where large volumes of freshwater are needed for electrolysis at a ratio of roughly three parts freshwater per one part energy thus representing the breaking of the energy water nexus. Accordingly, a combined cycle system will be used to further model the potential freshwater and green hydrogen production.