In 2012 we had a wonderful stay in Feldberg, in the Black Forrest in Germany.
As we were previously in Alsace, we took the ferry boat to cross the Rhine Rhinau-Kappel.
We booked the hotel Waldeck, a small familiy operated hotel in the upper black forest near lake Titisee and lake Schluchsee. (Clikc on the links for more touristic information about Lake Titisee and Lake Schluchsee). Lake Schlucsee is very large and Boat Cruises on this lake are possible.