Surfcasting and boats near shore

[Bocephus]

I know there are a lot of boat guys in here, but Id like to hear from shore guys also..... Is there a set distance for both boat and shore dudes to keep away from each other? Ive had quite a few times when I thought "Jeez, that boat can clearly see me fishing, but still comes back and drifts right thru where Im fishing" or worse, someone sees me catching and pretty much parks the boat on the spot in front of me. What do you consider the etiquette for these situations?

PS long time lurker, first time poster