The awkward uncooperative non-compliant personnel would often get the same service in return and it is very easy for ATC to give as they receive!!
I would be interested to know as I'm sure others will, how does that manifest itself to a pilot using your service.?
Notification of arrival and departure
17.—(1) If the commander of an aircraft has caused notice of the intended arrival of the aircraft at an aerodrome to be given to the air traffic
control unit or other authority at that aerodrome, he shall ensure that the unit or authority is informed as quickly as possible of—
The operative word is "IF" there is also a reference to "Booking out" which advises "Flight details will not be passed to another ATSU" unfortunately I think the CAA server must be down due to the Holborn fire? so cant give relevant CAP
The argument about the use of boats with no requirements like this are valid. Unless going to a foreign port no-one knows..