A video appearing to show surfing legend Kelly Slater riding waves alongside a shark has emerged online.
The footage shows Slater surfing in Margaret River, Western Australia when the 'shark' comes into sight at the 0.17 second mark.
Despite the potential threat of death, Slater does not flinch after the creature emerges.
The clip has been submitted for the GoPro Challenge Margaret River video contest, which features the world's best surfers competing in the Margaret River area known as The Box.
The area is an exposed reef break renowned for its heavy and powerful waves.
Slater, an American professional surfer known for his competitive style, has been crowned ASP (Association of Surfing Professionals) World Tour Champion a record 11 times, including winning five consecutive titles from 1994 to 1998.
He is both the youngest (aged 20) and oldest (aged 39) to win the title.
Slater, now 42, played the recurring character Jimmy Slade on eight episodes of the popular TV show, Baywatch, and has starred in many surfing films throughout his career.