I am also highly doubtful of any "slipperiness" qualities of graphite in a finish like this with respects to skin friction against flowing water. For it to do anything it would require enough friction to actually slide graphite molecules off the surface of the boat. Slippery against rocks, maybe, against water? highly doubtful.

Again see Mike and my comments regarding making a boat slippery vs getting the paddler strong. You will have much better results spending time doing sprints than spending time polishing or trying to otherwise tweak your boat. There are no fast boats, only fast paddlers.

I'm inclined to agree on the "slipperiness" factor, there are few things more slippery than water. But the exercise of sanding the boat - no matter how pointless - should improve strength for paddling.

So go ahead - "Wax On, Wax Off"