And on any case you don't need a transponder in D space which makes it easier to get into and through place's like YSBK, YSCN, YMAY, YCFS, YMMB, YMAV, YPPF etc. William town and Surfers are both Mil or Cspace so need a higher level of equipment. In any case ASA is proposing low level E-space in the Sydney basin to the west of YSBK down to 700 feet near the Lane North. This will impact both transponders and clearance from cloud base.