Looming from the depths, this huge creature looks as if it is about to swallow diver Sam Bester whole.
Luckily for her, it is actually a whale shark, which only eats plankton.
The picture was taken by Miss Bester"s friend Fiona Ayerst off the coast of Durban in South Africa.
The diver had been completely oblivious to the shark"s presence until Miss Bester pointed it out.
Whale sharks are the largest living fish species and can grow up to 65ft (20m) in length. Some experts believe they can live to the age of 100.
They are found in tropical and warm seas, typically with temperatures ranging between 18 and 30C.
And though the gaping mouth may look terrifying, it has a very practical purpose.
Whales sharks are able to gobble up huge amounts of plankton, sieving out the water swallowed with each mouthful through the gills.
Although they are so big, they are one of the world"s more elusive creatures and little is known about them.
Marine scientists dubbed them whale sharks because of their size. They have the skeleton of a shark and are therefore fish, not mammals.
Diver's close encounter with enormous shark - with picDiver's close encounter with enormous shark - with pic