The other day we had the pleasure of testing out Marine 31 Captain's Boat Coating. First we need to restore the surface so we went with a single step of sanding and followed it up with three steps of polishing. Our grit of choice was 1500 by had with 6 inch discs, foam interface and a hand strap...
Imo you should always wipe with Ipa or some kind of prep solvent to clean away left over polishing oils and allow whatever lsp your using to bond better.