Gelcoat is the original finish surface. From the photo, you have some serious oxidation of this surface. All I was suggesting is the easiest/cheapest way to cover the exposed fiberglass and prevent water from infiltrating. If you really want to restore this boat get some 240 grit sand paper and wet sand an area, follow with 400 or 500 grit wet sanding, then rubbing compound. If you dont end up sanding comepletely through the old gelcoat (to remove the oxidation damage) you MAY bring back the original lustre. If you're inclined, after this exercise, to do the whole boat you may consider the added expense and time of a gel coat repair.