I haven't been there, but my friend used to work there ,then later managed it. It's older from what I know but probably good enough for some wakeboard time in Germany. I know Allgau, Pfullendorf and Gundelfingen. Both Pfulli and Allgau are good. My friend now manages Pfullendorf.
Check out the land-locked surfing they do in Munich! It's crazy! It's in the English Gardens park.