I always tow with the cover on. I'm not a big fan of rock chips, road grime, oil, and any other debris on and in my boat! I don't have any issues with my cover rubbing on the fiberglass, it's a custom fit cover made for my boat. Also a cover is alot easier to replace than is carpet, upholstery, seats, etc. why have a cover if you're not going to use it? Not to mention if you need to pull into say a gas station, tackle shop, wal-mart, etc. and not have to worry that your electronics, rods, reels, tackle and everything else you own laying out in the open for anyone to just grab, at least with the cover they have to do some work to get into your rig. If you have a cover......USE IT!!