When youre in Lindau, drive to the island of Lindau. On the north-west end of the island is a parkingplace with a skatepark. there you will find a harbour wall - cross the wall - if there are waves, you should see it now...
Its a beautyfull place where you normaly think on everything, but not on surfing. But there are a couple days (all year round) when the lake produces mini-waves in clear water.Its fun "surfing" far away from the next saltwater, but it only works, when the lakewaterlevel is very low, means best in winter and spring.