sorry mate but if the locations of theses were known on the internet or any body in the hands of aquarium hunters they would be decimated in weeks, it took me over 4years to locate them and I had been at this location many times, the only way I found them was by them accepting me and this little dragon was hanging around for over 3 hours in very still waters, I was very lucky but I watched this one for over an 3 hours and I had only a mask and flippers on at the time I believe they shy away from the full diving equipment and noise.......
Should explain Im an underwater photographer based in Melbourne - amateur, but done hundreds of dives here and pretty well connected to that community here.
Several locations of these creatures are already well known on the internet, but if it really is close to Melbourne the location probably is a bit more risky as poaching does happen I agree. There has been the very rare odd juvenile that is found at Flinders pier, but they never seem to last long and the general guess is they've been blown in by a storm. I have never heard of anyone finding an easily accessible ongoing population in the Melbourne area, let alone over 4 years in recent times, there were reports of them being more common in the 80's.
Ive photographed them several times at Rapid Bay in SA which is one of the well known locations for them. They can be found down to 50m, although I have seen them there in 5m, so thats some pretty impressive snorkelling photography for 70 years old. They're actually very easy to photograph as they're very slow moving, the main issue generally is finding them as they have good camouflage in their habitat and doing it from an interesting angle and background as well.
Similar to others, some exif data and the full picture would be interesting to see.