He's behind you

When the gigantic shark snapped up the tuna fish that was dangling over the side of the boat, the tourists were delighted.

It was the picture they had wanted - them on deck, the monster in a feeding frenzy in the background.

But seconds later, their smiles for the camera turned to cries of horror... as the 14ft great white shark finished its lunch and tried to have them for afters.

Mouth agape, it suddenly surged out of the water behind them in a chilling real-life replay of those terrifying scenes from Jaws.

As it came within inches of making a meal of them, one of the tourists, Peter Otto, managed to get this staggering close-up picture of the fish's devilish dental equipment.

The brush with death took place on a shark-watching expedition in the Southern Ocean off Port Lincoln, near Adelaide, South Australia.

Conservationist Andrew Fox organises the trips, in which a baited line is used to attract the creatures, giving tourists a close encounter. But not usually as close as this.

Mr Fox and his father Rodney - who survived a shark attack in 1963 - use the expeditions to fund research on the great whites, which are in decline, partly due to overfishing.

Ironically, for all its terrifying power, the great white seen here looks doomed to become a victim of Man.

Those on the boat noticed it had an old fishing line hooked into its dorsal fin, trailing behind it and covered in seaweed.

It cannot be removed without risk to the researchers and is likely to mean loss of the fin, or death.