Most people recognize the basic beach flag system: green generally indicates favorable conditions, yellow means caution, red signals dangerous water, and double red means the water is closed. But the less familiar purple flag carries a different kind of warning. In some beach flag systems, it indicates the presence of potentially hazardous marine life.

A purple flag may be displayed when creatures such as jellyfish, stingrays, or other marine animals have been reported in the area. These animals can sometimes be difficult to see, especially when water visibility is limited. A purple flag does not necessarily mean the water is full of dangerous creatures, but it is a reminder to remain aware of what may be beneath the surface.

Purple can also appear alongside another flag color. For example, a green and purple combination may mean that swimming conditions are generally favorable while potentially harmful marine life has also been spotted. Unlike waves or currents, this type of hazard may be difficult for swimmers to recognize on their own, making the flag an important safety reminder.

If you see a purple flag, pay attention to lifeguards and local guidance, and avoid touching unfamiliar marine life. There is no need to panic, but the warning should not be ignored. The ocean is a living environment shared with many different species, and the purple flag simply reminds swimmers to enjoy the water while respecting what may be around them.