The 13th IFAC Conference on Control Applications in Marine Systems, Robotics, and Vehicles will be held online from September 22 to 24, 2021. This online conference is jointly organized by the German Institute for Information Technology OFFIS / DLR, the University of Rostock, and the International Federation of Automation Control (IFAC). The aim is to bring together leading scientists, researchers, students and industry representatives on relevant research topics that directly or indirectly deal with the broad field of maritime autonomy. In this way, the exchange of ideas and mutual cooperation will be promoted.