Whitewater is also like mtb in that there are varying degrees of difficulty. I've taken my rec boat through class 2-3 rapids on the Potomac below Seneca Creek. That was pushing the limits of my boat and my skills, but it was doable. Probably also a bit foolhardy (but fun ).

As for mtb, I'm still waiting for someone to give me a guided tour of Schaeffer so I can get to the next level without breaking my neck

And welcome, kmehrzad.