The largest breeding ground in the world for Great White Sharks is about an hour’s drive from Cape Town, in False Bay. It’s an exhilarating experience but please bear in mind it’s not without risks. Boats do capsize in the high seas around the Cape and people have been injured or died on these trips. However, considering the volume of operators, the accidents are very infrequent. Most travel insurance companies will not cover shark cage diving, though, and the indemnity forms are draconian!
In the summer, most of the sharks, particularly the Great Whites, are found actually out at sea, because their diet changes to fish. In the winter, you’ll be able to watch them hunting for seals and penguins, as you may have seen on the Discovery channel.