The shark, around 3.5 metres long, was photographed by Robert Hughes, who was trying to take a picture of some nearby dolphins.
Mr Hughes, who runs boat tours, was focusing his lens on the creatures when a young boy shouted “shark!”
He quickly panned round, capturing a shot of a thresher shark jumping clear of the water near Torquay, Devon.
Mr Hughes, owner of Devon Sea Safaris, said: “We were on our 8.30am morning wildlife tour with a full boat of 12 passengers when the sighting was made.
“We had just left some seals at Hopes Nose and started watching the short beaked common dolphins by Ore Stone when they began to act very strangely.
“I was waiting for a dolphin to jump and I had the camera ready when the 3.5m thresher came right into shot.
“It was one of the kids who spotted it first and when it breached the water for the second time I managed to get it on camera.
“The thresher is a beautiful creature and doesn’t pose any threat to humans.
“They’re not at all dangerous and would be very unlikely to attack someone.”
The thresher shark is a rare sighting in UK waters and is usually found in warmer climates in the mid-Atlantic.
The largest known thresher sharks reach a length of more than six meters and weigh 600 kilograms.
South West News Service
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