WATCH: Great White suddenly appears behind unsuspecting spear fisherman

Frightening footage shows a South African spear fisherman being swooped by a great white shark that emerges out of nowhere.

Video captured by the diver’s son during a salvage expedition shows the shark popping out of the water unexpectedly.

Seeming to appear almost out of nowhere, the predator bares his teeth and brushes the diver as it swims past.

The great white shark approaches the unsuspecting diver. Source: SA Spearfishing/Facebook

The white pointer gives the diver a tap on the head as it swims on without bothering to attack.

The close encounter has gone viral on social media, after being shared to the South Africa Spearfishing Facebook page late last night.

The predator takes the spear fisherman by surprise. Source: SA Spearfishing/Facebook

In just 18 hours the seven-second clip had already been viewed 1.5 million times, shared more than 30,000 times, with around 17,000 likes.

The video has sparked debate among viewers, with some saying the shark was playing with the diver, while others reckon the beast was looking for a feast. Others are adamant the shark was Photoshopped in.

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“Shark realised it wasn't food... his body language wasn't in attack mode,” one wrote.

“That's when his back is arched and pectoral fins are down.... in no way was he in danger..... makes shark more intelligent than us...!!!!”

Rather than making a meal out of the human, the shark bops him on the head and swims past. Source: SA Spearfishing/Facebook

Another agreed: “Beautiful to see. The shark clearly recognize the diver was not a prey item. Proof they are not mindless killers.”

Closer to home, a six-meter great white shark was on Monday spotted circling around a boat about 50 metres off Fourth Beach at Twilight Bay, in Western Australia.