Thread drift related to the report. On page 2 there is a footnote:
Aircraft are required to transit the Menai Straits below 1,500 ft on the Holyhead QNH
I didn't think there was any controlled airspace in that area, which seems to be confirmed by this very useful KMZ file from
Airspace ? 3D Airspace
So why the imperative "Aircraft are required ..."?