As others have said there are many options for boat rentals around the lake.
I've started putting together a list of all the links in one place.
Most places rent bowriders and pontoon boats. Goodhue Hawkins & Channel Marine have the largest boats (26-27ft) on the lake and I think Fay's has the only sailboats.
https://www.facebook.com/notes/boat-...18744308304430