Please, please, remember that it is folk, if you want to join an open session in a seaside town on the sea front in the middle of summer, please remember it is an open session. If you want a quieter more respectful session there are other places. Like the Rugby Club.
It is not as if it is not predictable. When they are fed-up with the Dukes they will wander and find things. Charge on the door and they will carry on wandering. Fill the place before 8pm and they won't be able to get in.

It is a jungle out there. Look for the clearings.