Different strokes...
...for different conditions. I have used vertglas (from Lovett Marine, on the web) with excellent results on a 1987 boat with badly oxidized gel coat. Practical Sailor reviewed all the acrylics over a three(?) year period and found them all good, with Poliglow coming out on top.My experience with Vertglas is that you MUST follow the directions faithfully and take no shortcuts. Their manual is explicit and detailed. After prepping with their compound liquid (like softscrub) and a non-abrasive scrub pad, supplied with the kit but I ordered an extra which I needed, and then with their wash which did a great job also, the trick is to apply the stuff in VERY thin coats, allowing it to streak. After 6 or so coats (they dry in a minute or so) I had a shine, and after 10 it looked like showroom.The Island Girl product is not for badly oxidized gel coat.If your boat is chalky and has a discolored waterline stripe, then Poliglow or Vertglas will do a fantastic job. No waxing needed, ever, just wash and recoat once a season to maintain the surface.Be aware, though, that there have been complaints of yellowing after three years. Practical Sailor used yellow test panels and so could not verify, and they have started a new test on white panels. My view is that folks apply it too thickly, with a wet applicator, and that sets it up to yellow. I spoke with a fellow who complained about it, yet boasted that he only had to put on four coats to get a good shine. Obviously too thick as Lovett state that you will need at least four coats to get ashine, and then after getting a shine you should apply at least four more.Hope this helps!