A close encounter with what may well have been a great white shark saw a diver scrambling to get back to his boat.
A clip shared on TikTok shows a young man leap into the Pacific Ocean in Encinitas, San Diego County, California, near a large shark as his pal films from the safety of the boat.
He and his friends appear to initially believe it to be a relatively harmless basking shark but on hitting the water he panics, realising it could be the more aggressive species.
The grey fish is seen thrashing in the water and, calling back to his friends, the diver - referred to as Ryder - says: "That was a bad idea."
One pal tells him to "get back to the boat", while he laughs and the shark slowly moves under the surface round the swimmer and towards the boat.
The diver shouts: "Ah! I touched it! Oh f**k."
The cameraman appears to begin telling his friend it's a great white before stopping short and saying: "That's not a basking shark, dude."
The footage, posted on Saturday, already has over 855,700 views, while after being shared on Reddit many users debated what kind of shark it actually was.
Basking sharks are the second largest shark species after the whale shark, both of which live on a diet of plankton, and are generally harmless to swimmers.
Great whites, on the other hand, can be much more dangerous.
"Who sees a shark fin and jumps into the water?" wrote one user.
Another said: "This is honestly the scariest video I think I’ve ever seen."
A third added: "Even the shark was like, 'Is this dude serious?'"
According to official figures, San Diego County has the highest rate among California coastal cities, including places like Humboldt and Santa Barbara.
