Abstract Electrical power generation plays an important role in maritime vessels. This power is usually provided by a multi-component system where the generation begins with the rotational movement of a prime mover, usually and Internal Combustion Engine, an electric generator and an assortment of power electronic components to process and regulate electrical energy. Due to the requirements of the application, i.e. power-on-demand to reduce fuel consumption and increase user comfort, all components need to be adapted to perform efficiently within a wide range of output power levels. For such a purpose a Variable Speed Permanent Magnet Generator (VSPMG) is presented as a solution that fulfills most of the requirements of the power generation stage. However, the design of such of generator is a long process where multiple variables intervene. The following paper deals with a rapid modelling and design tool that helps evaluate a VSPMG with concentrated windings in a quick, and relatively accurate, manner. This tool can be used to obtain a first draft design that can be perfected after further analysis. Analytical equations and experimental data are presented for validation. A simplified thermal model is also presented with the corresponding experimental counterpart. Finally, conclusions are given and next steps are suggested.@en