Some interesting events in Constance in 2011. (without guarantee)
Carnival - meeting of Southern German Carnival Associations in Constance: 20/01-22/01/2012 (More information in German).
Constance-Carnival: 15/02/2012 - 22/02/2012.
"Bodenseewoche" (sailing event): 31/05-03/06/12: "Maritime" event with more than a 100 oldtimer sailing ships. More under: www.bodenseewoche.com (German).
German-Swiss flea market of Constance and Kreuzlingen: 16/06-17/06/2012: Big, border-crossing flea market. More information.
Oktoberfest (October festival): 21/09/2011-07/10/2012: One of the many small versions/copies of the Oktoberfest in Munic. Wine, sausages and music in a big tent. More information in German.