I have ridden the Single Otter from Victoria to Vancouver, and it is a gorgeous flight - over water all the way, perfect for a forced landing in a single floatplane. Our baggage went by bus on the ferry - not much space in an Otter when you put the pax on board.
If the flight is carried out IFR (which it will probably have to, as RPT) on a cloudy day, will they shoot the approach to Canberra Apt and then go VFR to the puddle? Will CA$A insist on Flight Attendants? X-ray security at Rose Bay and at "Gough's Harbour"? Tarmac terriers in yellow "FollowMe" boats scooting around the water, examining boating people for not displaying ASIC? Big fences put up around Sydney Harbour to stop intruders?
Somebody in CA$A will be licking his lips as he contemplates the Fees and Charges applicable to this simple run. And Sydney Airports Corporation will be screaming about missing out on a landing fee.