Michael C. Scholl is a marine biologist specialized in sharks, very well known for his researches. He is also the Founder and Trustee of the White Shark Trust. In these pictures we can see him approached by a shark while he was paddling in a kayak. The images are really famous on the web insomuch as they have created many urban legends, like the one about a grateful shark who follows continously his human saviour!. The truth is simply related to the researches of Michael Scholl as we can read directly from his words:
"Sitting in a 3.8-metre sea kayak and watching a four-metre great white approach you is a fairly tense experience. Although we had extensively tested the sharks' reactions to an empty kayak and had observed no signs of aggression, this gave us little comfort as we eyed a great white heading straight for us, albeit slowly. Just a metre or so from the craft it veered off, circled and slowly approached from behind. It did this several times, occasionally lifting its head out of the water to get a better look. Then it lost interest, and as it continued on its way we were able to follow a short distance behind. Once we'd come to terms with having nothing between ourselves and a four-metre shark except a thin layer of plastic, our kayak made an ideal research platform for observing great white behaviour in shallow water. Its advantages are twofold: it is inconspicuous and appears not to cause the sharks to alter their behaviour for long, and it allows us to watch them in a natural situation, as it is not necessary to attract them to us with food."