Paul Marshallsea of Merthyr Tydfil, Wales, was barbecuing at Bulcock Beach in Australia when he heard bathers yell "Shark!" The 62-year-old tourist saw a shark approaching children and ran into the water, grabbed the shark, and pulled it away from the youngsters.
"My instincts took over and I just grabbed the shark by the tail.
"I know it was dangerous but it almost looked beautiful - you have got to have respect for a beautiful animal."
Helicopters and lifesavers on water bikes later lured the shark out to sea with the tide.
An Australian coastguard spokesman said: "We don't recommend manhandling sharks but this gentleman did a great job."