Holidaymakers in Ibiza are rethinking their beach plans after large snakes were seen gliding through the water at popular resorts. Footage posted online shows the reptiles, measuring up to 5.7ft, calmly cutting through the waves near Portinatx, a northern tip of the island once known for its tranquil coves and quiet charm. Now, some visitors are describing the scene as more horror film than holiday brochure.

One tourist, clearly unnerved, wrote: “Tremendous… I’m already terrified of taking a dip. Who would have thought this about 20 years ago?” The appearance of snakes in the sea may seem bizarre, but it’s not as rare as people might think — at least not in Ibiza.

According to Dr Antonia Maria Cirer, a doctor in biological sciences, the reptiles often take shelter in boats that are stored on land over winter. When those boats are relaunched for the summer season, the snakes simply slither off in search of land.

She explained: “It’s instinct. This situation causes a general alarm throughout the territory.”

The snakes themselves are not venomous, reported the Mirror — but that’s done little to calm nerves.

Several holidaymakers have said they no longer feel safe swimming in the water, with one couple sharing a video of their up-close encounter while drifting in a small inflatable.

They said in disbelief: “I didn’t know snakes could swim!”

Experts believe the reptiles are invasive and have already caused ecological damage elsewhere on the Balearic Islands, including wiping out an entire subspecies of lizard on Illot de s’Ora.

With temperatures pushing past 30C, snakes are more active and visible — and their presence is beginning to reshape tourist behaviour.

Beaches that were once packed with swimmers are now dotted with cautious sunbathers keeping their distance from the waves.

Whether this becomes a recurring summer trend remains to be seen. But for now, the fear is real — and the snakes aren’t going anywhere.