I'm just back from SA and we did have raggies on Aliwal Shoal !!!
No one knows why but 8 of them (probably subadults) decided to spend the summer there instead of migrating with the others...
We also saw a few tiger sharks, blacktips, guitar sharks and a lot of life on the shoal, from dolphins, turtles and rays to a great variety and quantity of small stuff, lobsters, nudibranchs, moray eels, etc... The reef is really nice and varied, all in all I had great dives there...
I also dove in Protea, had 2 very poor dives but one which was really amazing with a tiger shark, 7 or 8 blacktip, 10 bull sharks, 5 guitar sharks, potato bass, tunas, eagle rays and even... a whale shark !!!
There it seems to be all or nothing, unless you do baited dives during which bull sharks are guaranteed... the diving is more advances than in Aliwal, with strong currents and reefs averaging a depth of 30m, no time for contemplation, you dive in Protea in the hope of seeing big stuff.