I have not heard of any. The three "public" bodies of water are Bay Lake, Crescent Lake and the Seven Seas Lagoon. And with the ferry boats and yachts, as well as such things as the water mice, a sailboat would be an accient waiting to happen.
And also, to rent out a sailboat Disney would probably want to be sure the user knows how to handle one; a power boat (or water mouse) is a lot different for control.