When the weather is fine, you can set out on a great 2-hour boat tour exploring the south-western Havel lakes. In addition to restful natural beauties you can cross for example the castle Babelsberg, the Sacrower Heilandskirche, Nikolskoe with the church Peter and Paul, as well as the beach Wannsee.
If you would like to represent your feet and explore the beautiful corners on foot, you can easily combine the trip with a visit to the Peacock Island or a hike through the Grunewald.
Star and circle is the domestic and yard fleet of Berlin. From here you can start various tours over the Wannsee in the Havel. Also recommended is the start with the F10, a ferry of the Berlin BVG. The ticket costs here only the classic ticket. Short-haul is unfortunately not, you would have to get off in the middle of the Havel.