DHD yes you are correct, I shaould have realised the difference in reference points.
Has anyone plotted out the FIA boundaries from the DAH? It appears they are virtualy identical to the pre NOV27 boundaries except the vertical boundaries have been lifted from 5000ft to 8500ft (base of E). One thing is a bit wierd is the area for ML-CEN 123.75 which used to be for airspace above 5000ft to NE of ML has been reduced to an approx 10nm by 10nm polygon just outside classE near Yabba Nth on the ML VNC ( sorry about the visual ref). Anyone else found this?
At least now I have an idea of where the boundaries are, should make things a little easier to maintain a listening watch.
Regards
Mark