The HyFES (Hybrid Fusion Energy System) is a business led, collaborative project to further improve the benefits (lower fuel costs, reduced emissions) marine vessels gain from switching to a hybrid propulsion systems. HyFES is at the hub of an intelligent sensor network incorporating propulsion batteries, hotel/standby batteries and through the installation of Dynamic Resource Monitor (DRM) sensors, any other electrical equipment including engines and generators. HyFES will fuse together model and data based prognostic algorithms with algorithms designed to ensure optimal operation of system assets to ensure vessels make operational decisions based on through life costs of assets rather than focusing solely on fuel saving. The project brings together a consortium that spans the complete supply chain including Heriot-Watt and Southampton Universities, the High Speed Sustainable Manufacturing Institute (HSSMI), Custom and Contract Power Solutions (CCPS), Denchi Power, FM and MBNA Thames Clippers.