Kayaking
We went kayaking one afternoon in June for 7 miles down the Rappahannock River (about 3-3.5 hour trip if done at a leisurely pace). We were lucky that it was a mostly cloudy, not humid day. We often were the only ones on the river, and on both sides of the river were just woods (no development), so it was very rural and peaceful. The water was clean, and we saw fish, a snake, and a pelican. The kayaks were easy to handle, although the water level sometimes was low (I think due to the time of year), so we sometimes would get stuck, but it wasn't too difficult to free oneself. There were small rapids every mile or so, but nothing that exciting (no danger of flipping or anything), but again this might have to do with the time of year. Service was friendly. Just beware that they don't accept credit cards; just cash or check. Overall, I recommend the kayaking at Clore Brothers.