I hope you didn't have a confrontation. My dh and I were at BMB one day and this couple came and sat AT WATER'S EDGE - water seriously lapping at their feet and they were just relaxing and enjoying a day. When down rushed this "mad" woman screaming they they were on "her private beach". Then her husband came down and they were nuts - screaming and carrying on.
So the couple moved over like 1 foot to the east and then the house owners were satisfied. BUT they put up a chair to mark the line that couldn't be crossed.
It really bothered me to see such a production over people just sitting on the beach enjoying a beautiful day.
I'll be curious to hear more about what happened with you.
Gidget