Why You Might See A Purple Flag Flying At The Beach. The Hidden Warning Most People Ignore — And What It Says About Dangerous Marine Life June 7, 2026 by yassine ADVERTISEMENT are among the most common reasons purple flags are raised. Their tentacles contain microscopic stinging cells capable of causing burning pain, redness, swelling, and irritation. Most stings are mild, but certain species can trigger severe reactions. PORTUGUESE MAN O’ WAR These creatures are often mistaken for jellyfish, but they’re actually different organisms continue reading … ADVERTISEMENT ←PreviousNext→