When I am coming up on some bankies I generally like to watch what part of the river they seem to be concentrating on and go the opposite way. If they are fishing the middle of the river out, I will come in close to them and just the opposite if they are fishing middle in. So far this has worked for me this year, almost everytime I come inside and stay away from there water and have been thanked numerous times this year for doing so.
As far as with other boats, my opinion is that if a boat was in the hole a head of you then they have the right to fish it as long as they want. I will either fish the upper end of the hole and wait for them or I will go on by and skirt the outside to stay away from the water they are trying to fish. I do think though that once they have gone trough to the bottom they should let the next boat have a shot at the water, take as much time as you feel you need to fish it effectively though. If it is a crowded day,then move on down river. If there aren't a lot of boats on the water row back to the top and wait your turn. Just dont row back over the holding water. I saw a very impatient boat on Monday move in on top of a guy who was slowly pulling plugs back through a hole, this boat moved down and covered almost 200 yards of this hole in a matter of minutes passing the first boat within feet of it then moving directly below him by about 20 feet, right on top of where he was fishing and proceeded to zig zag across the entire river and spook all the fish out of the hole. One of the ruder things I had seen this year. Just be courteous and like the old saying goes treat others like you would like to be treated.