This tour is about 20 kilometers long (one way, 40 kilometers both ways) and it's quite flat. You start off in Constance and take the ferry (from the ferry harbour, not the harbour in the centre) to Meersburg. It's no problem to take your bike on the ferry.
If you have turned left, in about a quarter of an hour you arrive in Unteruhldingen (the cycle path leads right next to the lake). Right at the beginning of the village, there is a good fish snack-bar. At the other side of the village, you will find the stilt houses museum. A Stone Age village has been rebuilt in the lake. The entrance fee is 8 Euros and the museum is worth a visit, because it shows well, how people lived during the Stone and Bronze Age (about 4000 to 850 B.C.) at Lake Constance.
Then you go on the the baroque church Birnau, which dates back to the 13th century. The church, as it looks today, was built from 1746 to 1750. It is richly decorated inside. And from the place at the entrance, you have a good view on Lake Constance.
Then, the final part of our tour leads us to the centre of Überlingen. The town with its 22.000 inhabitants has a somehow "cosy" atmosphere. At the harbour there is a humorous sculpture from Peter Lenk about a well known German poem (about the completely frozen Lake Constance). To go back to Constance, you have three options: On a ship, by train or by bike.