I always wanted to do something like that. For the well-rewarded tour operators, there is no down side to shark viewing. Not only are the trips a boost for the local economy, the operators say, they also contribute directly to public awareness and concern for a misunderstood and endangered species. For others, however, the benefits are less clear. Three years ago a movement sprang up in Cape Town to ban cage diving and chumming, the practice of putting mashed fish and oil into the water to attract sharks to the boats.
Some scientists complain that chumming tourist boats have disrupted shark behaviour and research.
Dr Leonard Compagno, director of the Museum of South Africa's shark research unit in Cape Town, says the truth probably lies somewhere in between. The California-born Dr Compagno was, many years ago, technical adviser for the film Jaws . The Richard Dreyfuss character was, he says, loosely based on himself. These days he is philosophical about his role in making a film that hugely increased public awareness of sharks while playing up their traditional image as unstoppable, malevolent killing machines. The slaughter eased when South Africa became the first country to make the great white a protected species.