Probably a bad move. The police may not take any interest in ******* boaters, but they will certainly take an interest in someone shooting deadly weapons at them. If he DID call the police and you all had a little get together, it would probably go a lot like this:
Gary D: blah, blah, blah, so I shot my speargun at his boat.
Oink, Oink: So, you admit you shot your speargun at him?
Gary D: yeah, that's right. He was harassing us.
Oink, Oink: That's all I needed to hear. You're under arrest for assault with a deadly weapon. Put your hands behind your back.