However, Iíve never known one to last longer than wax.
really? Im surprised. I don't know which product you used, or how you applied it, but in my experience Zaino, applied correctly and once cured, is extremely hard and long lasting. It's far longer lasting than any wax that I've used. To my eye it gives a deeper shine too.
Don't get me wrong I used to be a huge Collinite fan. I used Collinite exclusively on my cars and boat for years. It is no doubt the hardest wax available and gives great, beautiful results. But it is a serious workout to apply and buff out. And while it will last longer than any other wax, I've seen that it cant compete with modern sealants.
About 15 yrs ago I tried Zaino on a recommendation from a friend in my car club and never went back. After a few years of using it on my cars I talked to the owner of Zaino and got some advice and tips for using it on fiberglass. The very first time the surface does need to be stripped of residual wax, etc, before applying. Prep is nothing crazy but these sealants can't layer properly on top of waxes.
Anyway I dont mean to preach or convert anyone. I know these things can be like anchor or motor oil discussions. I have no affiliation with Zaino, I'm just sharing my experience.
oh and for the record, use a mantus anchor, and Amsoil fluids in your engine and transmission or else you are doomed :-)