The issue I see is that unless you have a large outside storage compartment for it, you would have to bring it inside the RV.
Most RVs have a side door, so there's a sharp L turn that the surfboard has to maneuver. Depending on the layout, this could be impossible. I could get something 5ft long (maybe up to 6ft long) that is rigid into my RV. Anything longer than that, and I can't maneuver it around the L.
An RV with a rear door is the best option. My friend can load something like that into her little teeny chinook much easier than I can in my larger clipper - simply because she has a rear door with a straight run through the RV.