Mystery as hundreds of blue sea creatures invade UK beach leaving visitors baffled

Tuesday, August 4, 2026 - Hundreds of mysterious blue sea creatures have washed up on a beach in the UK, leaving visitors baffled. 

Beachgoers at St Bees in Cumbria have been left confused by the jellyfish-like creatures. 

The creatures have been dubbed “by-the-wind-sailors”. Also known as Velella velella, these creatures are closely related to the Portuguese man o'wars, but are significantly smaller and generally considered harmless to humans. 

However, people are still advised to avoid touching them.  

Their name derives from a fin that resembles a small sail. 

By-the-wind-sailors also possess short stinging tentacles used to prey on young fish as they journey. 

Local resident Louise Nicholson spotted them while enjoying a day at the beach. 

It's thought that the blue creatures were carried in by warm waters from the Atlantic. Initially she mistook them for an unusual type of seaweed and almost picked one up before deciding to take photographs instead. 

Louise said: "There were hundreds of them and there were lots of visitors to the area taking photos. 

"They are absolutely beautiful, only about five cm in size. It was a great find on a beautiful day." 

Louise sent the pictures to the Cumbria Wildlife Trust who have shared the images along with information about by-the-wind-sailors. 

The Cumbria Wildlife Trust said: "They're called by-the-wind-sailors and, as the romantic name suggests, they spend their lives drifting on the wind. 

“They're also not true jellyfish, despite the very jellyfishy appearance. The reality is far more bizarre – each sailor is actually a colony of polyps functioning as one organism, with various types of polyps performing different roles, such as feeding, reproduction and defence. 

"They're typically spotted along the coastlines of Britain and Ireland throughout autumn and winter when stormy weather strikes.”