honestly Rick If some one came up behind me I probably would not notice them, I tend to hyper focus sometimes that way. some times it is just an intent person. now on the flip side once my intention is caught I will wade back to shore and shoot the sh*t. light a smoke and offer the flask if I happen to be carrying it.
I find worrying about the bad manners of others ruins my day more than the bad manners. so i figure as long as some one is not in my cast range, who cares. If they are I just move on, light a smoke sip the flask and all is good till I find the next "must hold a fish spot"