This paper presents a new hybrid concept that increases the overall efficiency of the propulsion system on ships. The hybrid concept of the marine propulsion system was examined in 1D CFD internal combustion engine model where the turbine and compressor are not mechanically connected. Such a configuration makes possible different turbine designs than needed in the conventional turbocharger. The advantage is an increased recuperation of energy from exhaust gases. By means of computer simulation and optimization, this study proves that the hybrid concept significantly increases the propulsion system efficiency and lower emissions in maritime environment.