There is a fundamental need for naval vessels to address their moral responsibilities to the IMO’s requirement to reduce carbon intensity by 40% or more by 2030. Existing vessels have limited means to do this without immediate recourse to low carbon fuels, something not feasible for interchangeable operations with allies in a worldwide context. Energy saving technologies (EST)with technologies that reduce energy consumption therefore offer a means to reduce the ship’s energy efficiency index (EEI). The adoption of a combination of a wind propulsion device and microbubble drag-reduction on the BMT Venator frigate is explored to identify the benefits at a range of speeds and sea-states. The potential for other propeller benefits in term of higher efficiency and lower noise are explored together with the scope for reduced roll and how that may benefit rudder usage and resistance. The likely heel angles achieved with a steady side wind are also considered and their impact on added resistance scoped. The study identifies the beneficial impact of the EST on the ships EEI and identifies methods by which the EEI can be compared to other frigates so that EEI targets can be set for future designs. The increase in range is identified for the specific speed in the prescribed endurance conditions and the benefit of this to the ship’s ability to keep station identified.