This memorandum presents a simplified analysis of the active system power requirements for new submarine sonar. The analysis was performed in the new submarine sonar group for the purpose of indicating approximate primary power and transducer design requirements. The primary power and the power density required to produce a specific source level are functions of the geometry of the array, the efficiency of power conversion and the characteristic impedance of the water. The efficiency of power conversion is the product of efficiencies of the transducer and the power amplifier. The effect of the ordinary variation in the impedance of the ocean is insignificant.