Roanoke

We enjoy this very much, as novices but not absolute beginners. The lowest is 200 cfs, and you might get stuck on rocks a couple of times. It takes about 3 hours. When it is at 1200 cfs it flows much faster, closer to between 2 and 2.5 hours.
At 400 cfs there should not be a problem with shallowness. But that means there needs to be rain in the last week.

The hardest rapid is a 'dragon's tooth' on the right with straining rocks. Stay on the left of that and you should be fine. And there are a couple of small ledges that keeps you on your toes.