Current WI law states that:
Your boat MUST have mufflers AND maintain a db level not to exceed 86db. If they determine that you are running without mufflers, they do not even have to test you because you are already quilty.
I was stopped years ago and the DNR guy had a small briefcase full of goodies. First thing he asked me is "are you running mufflers", I was, the next thing he did was pulled out a db meter, PVC pipe and some fittings. He put the contraption together and measured my idle at <3' back> and <3'up> and took a reading. That was my last boat and it read 84db so he pushed away and said "have a good day".
What really gets me is the damn Harley's on the street. Damn near everyone out there is louder than any performance boat and everyone seems to praise them for being loud... go figure.
How to fight it?, I would bring up the Harley scenario and yell and scream at my Politicians.