The sun plays havoc with the gelcoat on my camper. Last year, I used Nu-Finish to restore the shine to my front cap....the sunniest side. I also began to notice some streaking on the port side of my camper last year.....the runner up for sunniest side. This year when I washed the camper, this is what the port side looked like.
And that is after going over the entire camper with a black streak remover and a magic erasure, along with a follow-up car wash solution. The back and starboard side (not as much sun) still look great, but time might even catch up with those sides.
I blame a lot of this on the roof chalking, running down the side during heavy rains when the gutter can't handle the load, then the sun just bakes it in. I started with Nu-Finish again, but had to go over each section 3 or 4 times to do any good. Looking for something a little easier, I found this a Wally World:
Premium Cleaner Wax : Attwood Marine
It still takes 2 times with each section, but this gets rid of the streaks much quicker. Hopefully, my camper won't turn yellow or the gelcoat deteriorate from using this, but I am going to give it a try on that entire side.
Here it is partially done: