I use usfountainone cleaner to clean the nasty iron stain that happens under the boat. I know wax is a no go, looking for something like maybe a polish that will prolong the hull and slow down the staining?

I use PowerOne cleaner as well. This Spring I tried an experiment with just the bow section. Maybe a 6 foot long section when it was on the trailer. I followed up the PowerOne with Starbrite's Cleaner Wax with PTEF and then Polish with PTEF. The next day trip I had after pulling it I was in shock. The area I put the wax and polish was bright white and the rest of the hull was the normal yellow/brown discoloration. That's the good news. The bad news is that over the 4th of July I was in a sleep for almost a week and when I pulled it the entire hull was the same discoloration. Moral of the story? If you are just putting in for the day, there is a definite advantage. Longer term it doesn't seem to make a difference. The saving grace is using the PowerOne again and just getting everything bright white again.

Yeah, pretty much what he said.... If you just dip the boat for the day using a polish will slow down the yellowing. However it won't prevent it. I plan to throw a quick polish to the bottom of mine so I can extend the time in between Power One applications. Also I have noticed using Power One diluted 50% with water seems to work just as good. Also using in a pressurized fertilizer sprayer seems to use the least amount of product.......

I've been using toilet bowl cleaner

But I'm worried about long term gel damage

I've used this for over 30 years but only twice a year. However I now have a white bottom and it really gets yellow quicker and I need to clean more often

3pointstar

I have never heard anyone doing damage using toilet bowl cleaner (I don't use it). However I do know it strips wax/polish. The Power One won't strip the wax/polish (so safe to use on the hull sides without having to reapply wax/polish). However Power One may or may not work depending on the actual stain/water you boat in.. Also Power One is not acid based like toilet bowl cleaner... I apply power one with a pressurized sprayer and aside from making sure it doesn't get in my eyes, I don't have to worry about gloves/masks/etc.. But again, it may not work for everyone.

I rack store my boat inside but the bottom will yellow after 2 months of use. I tested cleaning the whole hull till it was white with slimy Grimy and then use 1 coat of Collinite 885 paste wax on the bow section and it will keep the yellow staining away almost till the end of my boating season (October 1st) Ive done this for the past 4 seasons and I usually have about a week’s worth of overnights in a season. I would highly recommend the collinite paste wax in a can #885.

+1 on the Collinite 885 and I boat on the Mississippi River. Use Meguiars #45 polish at the beginning of the season to feed oils to the gelcoat and follow up with Collinite 885 paste wax.