Heart-stopping footage shows the beast’s dorsal fin poking out of the water in Puerto Rico as choppy waves crash around it – just feet away from the pair.
Two people in the water can be seen desperately trying to swim away as the shark thrashes in the water close by at Middles Beach, Isabela.
Surfer Rolando Montes can be seen making a panicked bid to paddle back to the safety of the beach while his pal also tries to get away on top of his board.
Stunned onlooker Jorge Benitez filmed the too close for comfort encounter as his friends fled from the massive predator.
He says sharks are rarely spotted in the area.
“This is the first shark I see,” Benitez said.
“Although it’s known they are around the areas, but apparently they have enough food so we barely have incidents if any.”
Shark attacks in waters off Puerto Rico are rare – with the most recent incident reported back in 2011.
It comes after the number of shark attacks explodes across the globe as swimmers continue to ignore bloodbath warning signs – seeing nearly 800 people mauled in just nine years.
America has overtaken Australia for the number of attacks with Cape Cod, Massachusetts, now considered the shark capital of the world.
Experts report seeing 50 in the popular holiday haven alone this summer.
However, despite a spike in maulings by the ferocious beasts and signs warning of attacks on beaches in the US and Australia, swimmers are still putting themselves at risk.
This year has seen 49 shark attacks – six being fatal – across the globe, as the underwater predators continue to get closer to humans.
The US recorded the largest number of shark bites, reporting 33 incidents, while Australia recorded 18.
A whopping 791 shark attacks have been reported between 2010 and 2019, according to data published by the International Shark Attack File, with an annual global average of 80 bites.
It shows an incredible rise compared to data from 1970 to 1979, when just 157 attacks were reported.
Surfers and water sports lovers seem to be the prime targets, accounting for 61 percent of victims last year.
Meanwhile, a researcher was astonished when he spotted a shark that was still hunting for its prey – despite being “half eaten”.
The scientist, who was releasing an oceanic black tip shark into the sea, was stunned as he saw the injured beast mauled in a cannibalistic attack.
Dr Mario Lebrato, 35, from Spain, said he captured the incredibly rare footage off the shore of Mozambique – some one to two meters below the surface of the Indian Ocean.
But as he and his group released the shark, a different group of predators set upon it, inflicting a series of fatal injuries.
Despite the onslaught and a large portion of its lower body missing, the shark continued to fight for its life as it was seen swimming away.