This final report summarizes the work carried out in the project Underwater Systems of Sensor Platforms during 2016-2018. The purpose of the project is to enhance the knowledge and technical support to the Swedish Armed Forces with respect to underwater sensor systems on surface ships, submarines and unmanned underwater vessels for reconnaissance and actions against sea targets. The project has focused on acoustic active and passive sensor techniques for mobile platforms. Research has been conducted to provide an improved reconnaissance capability and a foundation to enhance tactical support by studying new methods for signal processing as well as developing sound-propagation and sonar models. Furthermore, computer-aided methods for change detection has been studied as a possible support in future mine hunting operations. In addition, analysis and modelling tools for prediction and suppression of flow induced self-noise enabled by Computational Fluid Dynamics (CFD) have been developed in the project.