Casting Near Boats and Docks

[Greene's Basin Girl]

Last week a fisherman was casting by our dock and when casting his cast hit our pontoon boat. He came back on Saturday and casted right near our boat again. I asked him politely if he could cast away from our boat. He responded with words I won't repeat and casted again. That time he just missed casting into our PWC. I don't understand these people. We own 500 feet+ of shoreline so he had plenty of undeveloped land to cast around. I would appreciate your thoughts on this.