
Lemon Shark - Negaprion brevirostris
The Lemon Shark - Negaprion brevirostris can grow up to 3.4 meters length.
Although they have scary looking teeth, they posed no threats to humans unless 'provoked'. They are not likely to 'attack' humans be it divers, snorkellers, surfers and swimmers as they do not hunt in the manner like other bigger sharks like Great White or Tiger Sharks.
Close-up picture of the similar Shark can be seen here :

The lemon shark, ''Negaprion brevirostris'', is a shark in the family Carcharhinidae, can grow to 10 feet long. It is known as the lemon shark because light interacting at certain depths with the local seawater can give this shark a tanned and yellow, pitted appearance, much like the surface of a lemon.