I am a Cape Town local and do about 30 dives a year in False Bay. I have no problem with going to see the sharks breaching. I also have no problem with cage diving per se, although I do think it does tend to lend the impression that the sharks are not all that dangerous. While I do not think that they are man-eaters and mindless killing machines they are nonetheless still wild animals and the top predator in the ocean and need to be treated with serious respect. While the cage diving industry has cleaned up its act substantially over the last few years, many operators are still too casual with these animals and sooner or later someone is going to get hurt. The victim of all the bad publicity will once again be the shark. In many instances the researchers who advise the government on their policy towards sharks (which also brings in serious revenue for the government) are also the commercial operators who stand to gain the most from the operation. This is a bit like asking the wolf to guard the sheep!
But my real objection is towards chumming. There are those that say it does not condition the sharks and there are those that say it is responsible for the higher incidence of attacks we have seen lately. My own opinion is that it conditions the sharks to associate boats with food. When I arrive to dive nearby wrecks in the bay the sharks in the area associate my boat with food, come for a look, and the next thing into the water is me! While I have no scientific evidence of this, we have seen more sharks in the last few years than ever before. In fact, 10 years ago their were almost no reports of Great Whites seen by scuba divers. I do realise that the are more divers nowadays, but my contention remains.
Use the natural chum-slick produced by the seals on the island and watch the sharks by all means. Feeding of wild animals has long since been forbidden in terrestrial habitats, its time it stopped in the water...
Rgds
Jean