If you've seen two in the last month then you've missed loads.
The bloody things are all over the place. It is extremely hard to spot them even at the slow speeds that us SARBOY W**kers fly at. I am sure that they are going to catch someone out one day.
The one that was put up out at sea North of Rhyll was a single antenna about 240ft high. We fly IMC at 200ft over the sea and to say it didn't show up very well on radar would be an understatement.