Well, you know those guys around the world...for sure the Germans and Americans (esp. Hatteras) know it...the bird protectors !!!
There are some birds in the river mouth, and they want to protect the birds from getting disturbed by kiters!!!
So they placed those poles!
They did the same at the worldcup beach St Peter-Ording in Germany...around the swimmer's zone.
Well, the kiters who alway went in there caused it...
