I am looking for Holiday ideas and recall reading about a lake in France with campsite and a sailing school, but can't find it again.

Anyone have any suggestions?

And before you ask, yes I have done lots of google searches.

Tried Annecy? Nice little town with its own lake. Or is it a lake with its own town?

Annecy is fine. There is a sailing school and a big camp site at Saint Jorioz. about 10k from Annecy on the right hand side of the lake. Also right at the edge of town, on the same road there is the excellent municipal camp site & loads of sailing boats. I suppose there's a school there too (Les Marquisats).