In PA -
Requirements for vessel registration vary from state to state. In Pennsylvania, you must have a Pennsylvania Certificate of Boat Registration and validation decals to operate motorboats legally on public waters. In addition, unpowered vessels using Pennsylvania Fish & Boat Commission (PFBC) lakes, state parks, or access areas must be registered or have a launch permit issued by the PFBC or the Bureau of State Parks.
Not all waterways require registration though but all watercraft has to abide by the safe boating requirements.
If you want to talk about unsafe things, My dad used to pull us around with his boat and we sat on a section of plywood we found and tied the sky rope to it. If you didn't lean way back and pull up on the front .. well you can imagine what happened.
I am sure you could find info on your area as fast as I did on mine.