In recent years, both gasoline and diesel engines dominated the maritime sector, having the complete control of the market at any type boat level. Nowadays, the greenhouse gases and pollutant emissions have become significant issues that must be addressed. In this regard, many renewable energy sources have been proposed in order to reduce our dependency on fossil fuels. Among these, the hydrogen-powered fuel cells are definitely a promising solution, due to their zero emissions. This thesis aims to propose an high-fidelity and high-speed modelling of a fuel cell system for shipping industry. In particular, it's modelled an hydrogen-propelled Proton Exchange Membrane (PEM) Fuel Cell with all the auxiliary components that are essential for a correct operation.