Dr S. Peter Beerens is programme manager of defence research programmes on sonar systems and underwater acoustics. This includes the scientific coordination of various national and international research projects and product developments in the field of sonar signal processing and sonar performance modelling.With a background in theoretical physics Peter tries to bring sonar theory into practice. The complex underwater environment, in which sonars act, requires experimental validation of new ideas. Peter has been involved in many experiments at sea as manager, planner, organiser, executor and analyst.As part of his job Peter seizes opportunities to teach young people the art of sonar. Peter is a teacher at the TNO base course, TNO sonar course and for the sonar classes at the OPSCHOOL.