The Portuguese man o' war is a marine organism that can appear on beaches and represents a danger to swimmers. Although it looks very beautiful, its tentacles contain venom and can cause severe burns. The danger is such that even when the man o' war is already dead, its tentacles continue to function and pose a risk.
There is an international standard that indicates the use of purple flags on beaches to alert swimmers to the presence of dangerous marine organisms, including the Portuguese man o' war.
The Portuguese man o' war is not a true jellyfish. It is a colony of small organisms that work together in a coordinated manner. Its structure is blue or purple and resembles a balloon or sail filled with gas that floats on the water's surface, being pushed by wind and ocean currents.
