Originally Posted by paintman
Just how badly scratched is it?
If it's just minor scuffing to provide a key for the anti-foul system you'll probably get a decent result using a power polisher with a hard mop & a cutting compound - e.g Farecla G3 or similar. You could consider using fine abrasive pads to refine the surface before polishing - 1000, 1500, 2000 or 3000 grit are available - & I'd advise using a DA sander if you want to go that route.
If it's really badly scratched or other repaired areas become visible as you remove the antifoul then you might want to consider just re-antifouling it as anything else is likely to be a lot of work & as the area you'll be working on is going to be underwater in use is it really worth the time & effort?
Until i reveal more cant exactly tell, it looks dull rather than nice and glossy and shiny, will certainly give the machine polishing a go before going down the gel or flow coat route i think