Might not be the right thing to do but when it happens I run my trolling motor right thru their "hot spot". Happened last year @ lakeview. Guys pulled in right in front of me (10 feet) and started fishing the same log! They had to lift up their corks to keep them from getting tangled up in my trolling motor (you should have seen the mud I sitrred up). I started fishing again 10 ft in from of them w/o ever saying a word. They got the hint and left.