“…In the fourth approach, the leader-follower approach, a designated leader is followed by *This research is supported by the Amsterdam Institute for Advanced Metropolitan Solutions (AMS Institute), the Researchlab Autonomous Shipping (RAS) at Delft University of Technology, the European Regional Development Fund, as part of the Interreg North Sea Region project AVATAR, and by the project "GasDrive: Minimizing emissions and energy losses at sea with LNG combined prime movers, underwater exhausts and nano hull materials" (project 14504) of the Netherlands Organization for Scientific Research (NWO), domain Applied and Engineering Sciences (TTW). the followers respecting user-defined distances between the leader and followers [14], [15], [16]. The suitability of each approach depends on the purpose of the application.…”