Cage fight: Great white & diver in horrifying struggle after shark overshoots snack (VIDEO)

Horrifying footage has emerged of a great white shark thrashing through the water and bursting into a shark cage – while a diver was trapped inside.

The video, shot near Guadalupe Island off the west coast of Mexico, shows the shark lunging for a chunk of tuna that was tied to a rope.

The animal’s momentum then carries it forward and it bursts right into the cage – designed to keep divers safe from the maneaters.

At first there is confusion over whether someone was in the cage during the terrifying incident. A witness asks: "Is somebody in the cage?” Shock spreads around the boat when they realise it was occupied at the time of the shark incursion.

With the great white thrashing around chaotically inside the cage, one of the boat’s crew instinctively opens its roof.

This may well have been pivotal in saving the diver’s life as it allows the great white to escape through the hatch and swim safely away.

What feels like an eternity passes before the diver emerges from the water, miraculously unharmed though visibly shaken.

"My heart is going," he says, clutching his chest.

Despite the clear danger to the diver, the incident was unlikely an intentional attack from the shark. “What might appear to be an aggressive great white shark trying to attack the cage, this is not the case,” Brian Forrester, who videoed the incident, explained later on Youtube.

“When a great white shark lunges and bites something, it is temporarily blinded. They also cannot swim backwards. So this shark lunged at the bait, accidentally hit the side of the cage, was most likely confused and not able to swim backwards, it thrust forward and broke the metal rail of the cage.”

The diver was pushed outside the bottom of cage, “looking down on two great white sharks”.

“The diver is a very experienced dive instructor, remained calm, and when the shark thrashed back outside the cage, the diver calmly swam back up and climbed out completely uninjured,” Forrester said.

Forester told nine.com.au that the shark was spotted later that day and seemed unharmed after its incredible encounter with the diver and his cage. He also said that everyone on the boat returned to the cages the next day as they appreciated that what had happened was an extremely rare event.

The video was posted on the Youtube account of Gabe and Garrett, two Californian children. The account usually posts “family friendly content” such as toy reviews, superhero videos and “overall fun activities for young kids!”

The children’s father, Forrester, shot the video while on holidays and, despite the terrifying incident, says he wants to return to Guadalupe next year.