The use of fuel cells as a power source for propulsion can reduce the thermal and noise signatures of naval vessels drastically. However, safe and high energy-dense storage of hydrogen prevents this technology from being widely used. In this paper, a battery and hydrogen hybrid propulsion system fueled by NaBH4 for a small inland vessel is designed and evaluated using MATLAB Simulink modelling. NaBH4 is a hydrogen carrier that can react with water to produce pure hydrogen. The water can be produced on-board resulting in a high-density hydrogen storage option. In addition, the solid form of NaBH4 is stable under atmospheric conditions, leading to a safe hydrogen storage option. The effectiveness of the system is studied by defining three operational profiles and using these profiles as inputs to size the energy storage components. To regulate the power between storage components, an energy management strategy (EMS) is implemented. Finally, different configurations are used to estimate the energy density of the system. The highest energy density is found at 1.2 kWh/ kg and 1.3 kWh/L of hydrogen for a 100-hour range using solid NaBH4. The results implicate that using onboard produced water for the hydrolysis of NaBH4 can enable a safe, and energy-dense hydrogen storage unique to the maritime industry.