Abstract In EU FP7 project SONIC, partners set out in October 2012 to study the underwater radiated noise of ships and shipping. The objectives of the project were (1) to study the numerical and experimental techniques to determine the underwater noise; (2) to develop methods for mapping the noise of ships and shipping; and (3) to determine mitigation measures to reduce the underwater radiated noise. Numerical methods focused on determination of the cavitation extent and dynamics on propellers which is the main source of noise of commercial shipping. Research also focused on methods to determine the underwater radiated noise from machinery. Experimental methods in model test facilities have been studied and validated against dedicated full scale measurements. The ship noise source levels obtained from these numerical and experimental methods provide input to shipping noise mapping tools to determine the overall underwater noise in a certain sea area. Based on the experience gained in the SONIC project, a set of guidelines for regulators concerned with underwater radiated noise of ships were developed together with the AQUO project. These guidelines discuss the definitions, numerical and experimental methods and mitigation solutions for underwater radiated noise. This paper gives an overview of the work done by all partners in the SONIC project.