http://www.sharkattackfile.net/species.htm#tiger
The Tiger Shark is in the top 3 of the most dangerous sharks in the world. Free diving with them or trying to interact with them is just plain foolishness.
The Bull Shark is the most dangerous. Severe case of cranky pants on that species. Extra special bonus- they can survive in fresh water too! This is the species responsible for the Matawan Creek attacks in 1916 that the novel
Jaws is loosely based on. Some of the attacks happened several miles inland in the fresh water part of the creek. There was even a Shark Week special a few years back where they guy giving an interview about bull sharks, and standing in a lagoon full of them
, is attacked and almost dragged out to sea. All caught on film.
Number two is the Great White. If you look like a seal from below (surfers I'm talking to you!) you are at risk for an exploratory bite. Of course a nibble from a 12 - 20 ft. fish with a mouth full of dagger shaped teeth is not anyone's idea of a good time.
Again not the shark's fault. You enter the ocean, you are at risk. No different than if you were strolling along the African Plains and were attacked by a lion......