The sun bakes my gelcoat especially the stern portion which takes a direct hit all season. The colors at the bow are still factory fresh due to very little sun light. But after the registration numbers, it takes a beating.
As for the hull, this year is my last year of my favorite bottom treatment. It is no longer mfr'd. So simple. Just one little thin coat and that's it. While it doesn't prevent slime growth, it slowed it down a lot. And, made it very easy to brush it clean during the season. Usually if I'm anchored at the beach or out in the lake, I'll jump into the water and give it a scrub. I've never had any muscles grow on the hull.
Without this stuff, I don't know what I'm going to do next year. VS721 works just as well as above but the application process is extremely annoying. Having to put two coats of the thick paste isn't easy while climbing around underneath while still on the trailer. Then having to raise the boat off the trailer to get at the bunk areas......not any fun. But that's next year.