we dont use the cover on short trips,if you have a CUSTOM COVER MADE FOR YOUR BOAT,it can save you fuel mileage,it can create a vacuum inside the boat which can create drag,it also will keep the interior clean,exsp. if you tow with a deisel,that road grime is a pain to get off the carpets and seats after a few thousand miles,also that old saying"out of site,out of mind" will keep people honest when you stop for fuel,food,or motel 6,be sure to inspect the trailer completely also before you head out,we just got back from the midwest,and seen at least a half dozen boats with trailer problems sitting on the side of the road...brushhog