I recall a product called Polyglow years ago, might still exist, that sounds similar to yours above. It was like a liquid floor polish that produces a nice shine, but gradually yellowed, and then required a special liquid remover to remove back to the gelcoat. Most of us avoided using it.
I'll be interested to see what others think and suggest.
Frank
Thanks for the reminder of the "Polyglow" debacle. I note that a few owners did like it, but not a significant %.While I also love the "idea" of a product that relieves me of time and effort, (AFAIK) restoring gel coat shine takes technique and real labor. That makes me a skeptic, perhaps.
There are several prior threads here about the challenge of renewing that shine. Try a search on gel coat buffing, for instance.
Here is one thread:
https://ericsonyachts.org/ie/threads/restore-your-hull-without-painting-it.5649/#post-35064
In our early ownership days, we did restored our hull shine. I rented a buffer with several covers, used Finnessit followed by wax. With a friendly boat yard manager lending us their battery powered scissor lift for a weekend, we spent two tiring days working, and did get it mostly back to a mirror shine. Absolutely Fabulous --- for about a year.
Years later I paid $$ someone to do that again. It's either your money or your time... or maybe both.
Thing is, once UV has microscopically eroded/roughened the surface, only buffing down a bit will smooth it out again. And, you can only do that so many times before you run out of gel coat. At somewhere around three decades, painting becomes necessary and while I have also seen an old hull restored to "near new shine" by spraying on new gel coat and then buffing it out, it was very labor intensive.
OP, do let us know how this product works on your boat. And best of luck.
As Red Green used to say: "We're all pullin' for ya, and keep your stick on the ice!"