{"id":70279,"date":"2026-08-13T09:29:35","date_gmt":"2026-08-13T07:29:35","guid":{"rendered":"https:\/\/www.sea-help.eu\/news-general\/portuguese-man-of-war-what-to-know\/"},"modified":"2026-08-13T09:29:35","modified_gmt":"2026-08-13T07:29:35","slug":"portuguese-man-of-war-what-to-know","status":"publish","type":"post","link":"https:\/\/www.sea-help.eu\/en\/guide\/portuguese-man-of-war-what-to-know\/","title":{"rendered":"Beautiful, blue \u2013 and best not touched: <\/span><\/span>The Portuguese man-of-war reaches Europe’s beaches"},"content":{"rendered":"

It looks almost too beautiful to be dangerous. A small, blue-violet shimmering body drifts on the surface of the water, above it rises a translucent crest like the sail of a tiny ship. But anyone who swims closer out of curiosity during a swim stop should quickly gain distance: the Portuguese man-of-war is one of the most unpleasant encounters you can have in European coastal waters.<\/strong><\/p>\n

In July 2026, numerous specimens of Physalia physalis were reported along Spain’s northern coast. Beaches in Bizkaia and Gipuzkoa in the Basque Country were particularly affected; within just a few days, 19 injuries were recorded there, and three of those affected had to be taken to a medical facility. Portuguese man-of-war also appeared off Asturias, including at the beaches of San Lorenzo, Poniente and Arbeyal near Gij\u00f3n. Reports from the French Atlantic coast followed in late July and early August. There, sightings occasionally led to swimming bans and beach closures.<\/p>\n

This is certainly relevant for skippers. That’s because Physalia physalis lives exactly where we most like to be when jumping off the stern: on the surface of the water.<\/p>\n

Not a jellyfish \u2013 but a floating colony<\/h2>\n

Even though it is almost always referred to as a jellyfish: strictly speaking, a Portuguese man-of-war<\/a> is not a jellyfish. It belongs to the siphonophores, colonial organisms made up of highly specialized individual organisms that function together as a single creature.<\/p>\n

The most striking part is the gas-filled float, usually ten to 30 centimetres long, known as the pneumatophore. Its raised crest functions like a sail. As a result, the man-of-war cannot swim deliberately against wind and current, but is instead carried across the sea’s surface.<\/p>\n

But hidden beneath this comparatively small “sailboat” lies the real danger: long tentacles covered in countless stinging cells. They usually extend several metres deep, or trail behind the animal; under favourable conditions they can grow considerably longer. That’s why a simple rule applies at sea: don’t just avoid the visible blue float, but keep a very generous distance.<\/p>\n

Actually a resident of the open ocean<\/h2>\n

Physalia physalis is found worldwide in warm tropical and subtropical marine regions. For Europe, the Atlantic population is particularly relevant; in the Azores and in Portuguese waters, the species is by no means exotic. Wind and surface currents can carry the animals all the way to Europe’s Atlantic coasts.<\/p>\n

The Mediterranean is not entirely new territory either. Scientific studies show that Portuguese man-of-war repeatedly enter the Mediterranean through the Strait of Gibraltar. Sightings have been documented since the 19th century. In most cases, this apparently does not involve a permanently established Mediterranean population, but rather animals that are carried far to the east by particular combinations of wind, current and Atlantic water.<\/p>\n

Portuguese man-of-war were also observed in the central Mediterranean in 2026: between early February and early March, scientists documented specimens whose appearance was likely linked to an inflow of Atlantic water and particular current conditions.<\/p>\n

So the animals don’t “migrate” to Europe in the classic sense. They sail here \u2013 or rather, are sailed here. Wind and current determine their course.<\/p>\n

For skippers: look first, then jump<\/h2>\n

The danger is easy to underestimate, especially during a swim stop at anchor. While lifeguards at supervised beaches can raise warning flags, there is no one in a secluded bay to look out for man-of-war beforehand.<\/p>\n

That’s why a quick look around the boat should be second nature before jumping in. A Portuguese man-of-war is usually fairly easy to spot thanks to its blue to violet shimmering float. It gets trickier with individual or torn-off tentacles \u2013 these can be almost invisible in the water.<\/p>\n

If a man-of-war is spotted, the crew should not go swimming. Even a supposedly sufficient distance of a few metres is no guarantee, since the tentacles can extend well beyond the visible body.<\/p>\n

Anyone who sees several animals should skip the swim stop altogether and, if necessary, choose a different anchorage<\/a>. A cluster on the surface can mean that more specimens are drifting in with the wind and current.<\/p>\n

Caution on the beach too<\/h2>\n

Portuguese man-of-war are regularly washed up on beaches. There, they quickly lose their elegant shape, but their stinging cells don’t automatically lose their effect. Even dead or drying animals, and torn-off tentacles, can still sting.<\/p>\n

That’s why the rule is:<\/strong> never touch \u2013 not even with bare feet, a towel, or out of curiosity with your hand. This is especially important for children and dogs.<\/p>\n

A stranded animal should not be carried back into the water yourself. At supervised beaches, inform lifeguards or beach patrol staff. If several specimens are found, this is also a clear indication that more animals may be present in the nearshore water.<\/p>\n

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