Hoping to spruce up the Hull's finish

[TinPig]

Anyone have a suggestion for a product that will bring the life back to the finish of the gel coat to my 1987 Bayliner Trophy? Looks like very heavy oxidation. I've tried some stuff from Atwood, but it didn't take it out of the White of the hull. It worked great on the Blue stripes. When I've tried products, they still leave oxidation you can actually scrape with your thumbnail.
All advice appreciated!!