The flagship tour is Gray Line Zurich's "Black Forest, Titisee & Rhine Falls" day trip (operated by Hans Meier Tourist AG). A typical run departs the Sihlquai bus terminal ~200 m behind Zürich HB, drives north through Swiss countryside and across into Germany to Titisee-Neustadt (about 1.5–2 hours of free time, plus a cuckoo-clock demonstration at the Drubba showroom), then returns via Lenzkirch and Schluchsee with a stop at the Rhine Falls (about 45 minutes, optional boat ride at extra cost) before returning to Zurich.
Included: the coach, an English-speaking guide and the cuckoo-clock demonstration. Excluded: lunch, the Titisee boat ride and the Rhine Falls boat ride (extra, pre-paid to the guide). Maximum ~60 travellers, with free cancellation up to 24 hours before.