The key is the post by the MP, it is very clear!
As he stated, the "No Rafting Zone" NRZ is actually misnamed. It's not that you can't raft, it's that there are restrictions to how you can raft! It should be renamed "RRZ" (Restricted Rafting Zone).
In a NRZ, you must be 50 feet from any boats that are rafted. This goes for the non rafting boats too. You also must be 150 feet from shore, unless otherwise stated (i.e.: Braun Bay). Two boats can raft together in a NRZ, but more than two are not allowed.
The law doesn't state any escape for someone that 'was there first'. So if someone comes up and anchors (or swings on their anchor, or drifts) into that 50 ft zone, both of you are violating the law.
I find it helpful to discuss laws like this one, it helps to clarify the laws in my mind and acts as a refresher and to cement them there.
Now.. if a particular NRZ is under legal debate, well that's a whole other thread! LOL