Incredible footage shows a gigantic shark, thought to be a great white, circling around a small boat.
The clip shows the sinister fish's pointed fin poking out of the water as it moves very slowly towards the vessel.
It then appears to be investigating what the boat is and prowls close to it without being aggressive, Star Online reports.
The amazing video clip was captured by Salvatore Sicurello off the coast of Lampedusa, one of the Pelagie Islands in southern Italy, and posted on Facebook on May 23
Salvatore said he thinks the shark was up to six metres (20ft) long.
Patrick Jambura, a shark expert, shared the clip on his own Facebook page and was initially sceptical it was a great white - believing it could be a mako.
However he changed his mind, saying: “This video of a supposed great white shark, Carcharodon carcharias, was taken in front of Lampedusa.
“The verification of the species is still pending, since makos and white sharks can look very similar and we do not want to jump to conclusions here.”
Later he said: “So far we have corresponded with some colleagues with the result that it is really a great white shark.”
The footage has been shared more than 2,000 times, with people expressing their own opinions about the uncomfortably-close apex predator.
"Mamma Mia," commented one on Facebook.
Someone else joked: "I bought a boat today. But I guess I'll stay within a mile."
A self-styled shark buff claimed the animal was targeting the boat because it had learned to associate them with scraps of food.
He wrote: “Sharks are among the few method-learning animals, a bit like seagulls around fishing boats while cleaning their nets.
“Do you know why it is stationed around the boat?
“Because somewhere in the central Mediterranean, he learned that food falls into the water every now and then and patiently waits.”
Last week a swimmer was spotted within inches of a huge shark, also estimated to be around 20ft, in nail-biting footage filmed off the coast of Malaga.
He appeared to have no qualms about getting within inches of the animal as it glided past him in the water with its tell-tale fin showing.
The video shows the man bobbing about in the water close to the shark as it swims within a few inches of him.
The shark then swims past him, prompting him to dip below the water to get a better look before it swims off.
