This is a normal
repair for a car. Virtually all automotive
paints are repairable and most are blendable.
Check some autobody forums to learn more about these types of
repairs, but here are the basics.
Clean the entire area with wax, grease, and silicone remover.
Sand down the gouge with 80 grit, keep it feathered out.
Fill the gouge.
Sand down the
repair with 40 and then 80 keeping all your scratches in a small area.
Sand the entire abraded area with 150 and then sand a couple inches farther out with 320.
Prime over all of the 80/150 scratches keeping ALL of the primer inside the area of the 320 scratches.
Sand the primer and the 320 scratches with 400 wet.
Sand 6-8" around the 400 with 1000.
Clean again with wax and grease remover.
Tack rag.
Paint, keeping all of the
paint inside of the 1000 grit scratches. When you
paint, put the first coat covering just the primered area, the second an inch farther out, the third another inch farther out, tapering the edges on each coat.
Let the paint dry for 24 hours.
If it's really rough sand first with 1000, then 1200, then 1500 and polish.
Any decent autobody store will have a dupont camera that they can bring out to your boat and take a picture of the paint and the computer will match it for you.
You'll be doing all of your shopping at the autobody store here, the boat stores won't have all of what you need.