I believe that I saw the same stingray (or stingaree) at Port Noarlunga reef on two separate dives two months apart. During my dive there on 7th November 2015, I took these photos of a ray just right of the jetty:-
It seemed to me that part of the ray’s tail was missing.
Two months later, on 6th January 2016, I took these photos of a similar ray off to the left of the jetty:
It seemed to be the same ray, with part of its tail missing. I’ll be keeping an eye out for the same ray on future dives at Port Noarlunga reef.