An "enormous" 18ft shark caused some swimmers to flee the water as it emerged at Lantic Bay near Fowey, Cornwall.
While it might look a little scary, the gentle giant was a basking shark, which are harmless to humans.
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Tom George, 24, was onboard his boat with fiancée Cory Tibby, 21, on Sunday afternoon and managed to get some footage of the beautiful shark.
According to the Plymouth Herald, he said: "We saw this beauty of a basking shark – it was enormous, nearly as long as my boat which is 18ft.
"All the swimmers got out of the water pretty quickly."
Hannah Handscombe saw the shark from the beach and told the West Briton: "It was an amazing sight.
"The swimmers all ran out of the sea despite knowing it was probably harmless and everyone just stood and stared."
The basking shark is the second largest living fish, after the whale shark, and one of three plankton-eating sharks along with the whale shark and megamouth shark.
Adults typically reach 20 to 26ft in length, and they are usually greyish-brown, with mottled skin.
This shark is often seen close to land, including bays with narrow openings. The shark follows plankton concentrations in the water column, so is often visible at the surface. It characteristically migrates with the seasons. The basking shark is found from the surface down to at least 910m (2,990ft).