Shark Cage Diving has split the local scuba diving community in two. There is a clear divide between divers who are completely against it, and the one's who argue that it does not do any harm, and may even benefit the sharks in the end.
Arguments against it are that the practise of chumming (throwing dead fish and blood in the water to attract sharks) attract more sharks to the area than would have been the case naturally, and this argument is has been fanned on by spikes in attacks on surfers and swimmers by great whites. Another argument against it is about the fish/animals that gets to have the unlucky role of being the actual chum. There have been reports that 7 gilled sharks have been used - to the dismay of each and every single diver. 7 Gilled Cow Sharks are very primitive sharks - some say the most primitive of all sharks - and they are a favourite amongst divers. They are relatively harmless - almost no teeth - and we have come to love out little local colony of 7 gills living of the coast of Simonstown.
Then there is also the argument that we are interfering with nature - feeding sharks is the same thing as feeding baboons - it is bound to have negative consequences in the end, and alter their behaviour.
Proponents for sharks cage diving argue that it creates more awareness regarding great white sharks. People don't care about things they do not love, and you cannot fall in love with a shark without being exposed to it. We still suffer from the curse that the movie "Jaws" has brought upon us - fear of the great white - and by exposing people to the great white, we can create an awe and love for the shark, which in the end will hopefully help change our perception of the shark, and ultimately save it from extinction.
Apart from that, the argument goes, it has also created a lot of local jobs - there are 7 different Shark Cage diving companies, with numerous booking companies, transportation companies, guest houses, etc, all feeding of Great White tourism.
I myself have went on one of these Shark Cage dives. Having seen them personally did indeed make quite an impression on me - on that day, looking into the sharks eye, I realised that I would never want to see one of these under water while not being in my cage.