Sorry to hear As a bank fisherman (most of the time), I have never had any problem with boaters, and I have never tried to push them off a spot.

And you say "twice in a row?" What's with that? I am not even remotely suggesting that you are doing any wrong, but is there a possibility that you could find a way to fish your spot without being in the way of the "bankies"? It's not your responsibility, I know, just a possible solution.

At any rate, your bad luck can't continue without ruining the peace of fishing, I would think. Best to you.