Beachgoers in Australia's New South Wales fled the water on Wednesday when an eastern brown snake, the world's second most venomous snake, swam out - right between the flags.
"Tourists and locals fled from the water after the whistles were blown. At first people were concerned it may have been a shark, only to discover a 1.5 m brown snake," Olivia Moffatt, who was was visiting the Great Lakes region, told the Great Lakes Advocate in an email. She also captured the incident on camera.
The eastern brown snake, Pseudonaja textilis, emerged at One Mile beach at Forster, sat in the surf for a while and then slithered along the sand towards the beach.
Eastern brown snakes can grow up to around 2.5 metres in length and are responsible for the most snakebite deaths in Australia - but they generally only strike when they're threatened.
Still, it was a good idea for lifeguards to direct beachgoers away from the snake, Stuart Kozlowski, a reptile keeper at Sydney's Taronga Zoo told Oliver Milman from the Guardian.
He also explained that although land snakes often do swim to cool down, it's very unusual to find them in the ocean - usually the realm of tropical sea snakes.
"Their habitat is often near the beach, they like to spend time underground in the sand dunes… They quite frequently go into creeks and rivers to cool down and assist with the shedding of skin, but it's unusual for one to go into the salt water," Kozlowski told Milman.
"I think it was maybe cooling off or perhaps it was frightened and made a beeline for the water. Some snakes adapt to their environment so it may be a regular thing for this snake."
Of course, if Australia didn't have enough deadly things in its oceans to worry about - saltwater crocodiles, box jellyfish, great white sharks, just to name a few - this means next time you're taking a dip, you now need to think about the possibility that a land snake could be body surfing next to you.