It sounds like there was not a good bond between paints, hence the power-washer chipping it away.
Some ablatives are not compatible with each other. Unfortunately, you'll probably want to take it down to the barrier coat, if not the gel coat or fiberglass someday. But for now just repairing the chips will do.
Well, it's possible the prep wasn't very good. You never know with the yard, though it was a yard with a good reputation. The paints are both Petit, and are listed on their site as being compatible. But of course prep is just as important.
...Unfortunately, you'll probably want to take it down to the barrier coat, if not the gel coat or fiberglass someday. But for now just repairing the chips will do.
By the way, I meant to add to this post that I'm not against eventually stripping. But we have a very long maintenance list this year, since the boat is basically new to us, so if we can sand and paint this year without causing any harm
, then it's the way to go. Less than ideal would be OK with me, so long as the bottom doesn't foul and we're noting causing more problems. There are other things on our list that are more immediate, and need to be done this year.
Out of curiousity, is there a way to strip safely while leaving the barrier coat in tact? I assume so, but just asking for future reference.