Rollers weren't the cause - it's delamination from water intrusion.
Since you keep it in the water, Tony, this is more of an issue. If you only trailered it in and out every day I would have said don't worry about. So, the issue is that fiberglass can absorb water whereas gelcoat does a pretty good job (well, especially, the newer stuff) of keeping the water out. Even the older gel was better at keeping water out than fiberglass. So, what's going to happen - and has been happening for probably the whole time you've had the boat - is water will continue to seep into the glass and in between the glass/gel causing the delamination that you see.
It's not a particularly "hard" job to do a basic fix here. I assume you'd just want it to be solid and not too worried about aesthetics. It's just a time consuming job and awkward since you're on your back... or maybe your son will do most of the work? In a nutshell, get rough with it - scrape and chip off as much as you can. Then sand (just about any smaller sanding tool can be used... easier to control than something larger) all of the edges until you are POSITIVE that the gelcoat to fiberglass bond is solid. Give the old/exposed fiberglass a quick sand, too.
At this point, there are multiple ways to finish this, but an easy way would be to mix up some epoxy and simply paint a few coats on, letting each one soak in. Epoxy will fully seal everything up, it's easy to work with, and is 100% waterproof. You could even tint the epoxy to closely match the gel, although it won't be perfect. But this will cure the issue and you won't have to worry about future water intrusion. It won't be a perfectly smooth surface, unless you thicken the epoxy and take the time to sand it smooth... but honestly, the slight imperfections that will be there won't cause any performance issues.
To make things easier, you may want to remove the trailer and block the boat.