I recently bought 2 used Hobies. Met the guy at dusk and didn't give them as good of an inspection as I should have before I made the purchase. The next day I started looking them over planning all the mods I had been scheming on. That's when I noticed that the bottoms were pretty bad scarred up. My question is should I just let it be or will it cause enough drag to justify hitting with some real fine sand paper to slick them back down? Or is sanding them back smooth a bad idea?