At watts bar there is:
Watts bar dam I believe has a campground
Bbmarina.com (they say they have campgrounds, it's not the best looking place but if your into wakeboarding it has miles of smooth water! I live on the hiwassee river and it has awesome quality water up river)
I know of a semi private campground on the other side of the river from b an b marina that I can probably get you into (gfs family has a camper there)
Parksville lake is also a national forest, been told it has super clean water and is nice to boat at.
Let me know if you decide to come this way an camp I know of one place also to camp at over on watts bar lake that you get there by boat, parksville lake I've been considering taking a tent an camping out up there this season as well. Then in July center hills lake 18-20 if I remember correctly wake fest is going on an it's south east of Nashville.