Tech billionaire Mark Zuckerberg has been spotted having a surfing lesson in Hawaii, where he owns a sprawling estate.
The Meta co-founder, 37, enjoyed some group tuition in Honolua Bay, Maui earlier this week.
Zuckerberg, said to worth around $116billion, was spotted among the waves on the morning of December 15.
A holidaymaker filmed him surfing alongside a pier at around 7am - and described his skills as "not terrible".
Zuckerberg appears unsteady on his feet in the footage, and holds out his arms for balance - but remains upright on the board.
The eagle-eyed onlooker said: "I didn't originally realise it was him until he came up quite close. He was surfing just a few feet away from me at one point.
"The surfers already had my attention by this point because it's unusual to have so many people surfing right next to the pier."
The woman said Zuckerberg was in a group lesson with around 20 other people who looked to be "all a similar age to him".
"I worked out it was him because I could see the surfing instructor was paying attention to one particular person more than the others," she continued.
"At one point he popped up and everyone cheered. That was when I recognised his face from seeing him in the news."
She said Zuckerberg was "not terrible" at surfing - although she did spot him fall into the water once.
Shortly after, the woman said Zuckerberg called an end to the session and the full group piled into several nearby vans.
The social media mogul purchased 600 acres of land in Hawaii last year - meaning he now owns more than 1,300 acres of the paradise state.
The witness said: "I knew he spends time here but I was still surprised to see him. It was pretty cool."