The Double Red Water site is closed to the public. No entry. Violators are exposed to a fine or emergency intervention.
Presence of harmful marine species (jellyfish, rays, sea lice, etc.). Swimming at your own risk.
Important: Some beaches also use a red to yellow flag to indicate the presence of lifeguards (but this is less common). Always check local signage, as flag systems may vary by region. Geographic reference
What does the purple flag actually mean?
The purple flag indicates the presence of dangerous marine species in the area. Geographic reference
What is considered a “marine pest”?
Jellyfish (various species, some very venomous)
Rays (their barbed tails can cause painful injuries)
Sea lice (tiny jellyfish larvae that cause painful, itchy rashes)
Physaline (it’s not a real jellyfish, but it is extremely painful)
Fire coral (causes burning rashes)
Sea urchins (their quills can puncture the skin)
Weaverfish (venomous thorns)
Sharks (rare, but some beaches use purple to signal the presence of sharks)
What the purple flag does NOT mean:
The water is closed (swimming is still possible). Bottled water.
The beach is dangerous (be careful).
It is guaranteed that you will encounter harmful marine species (this is just a warning, they have been spotted).
The key word: vigilance. The purple flag is not a ban on swimming. This is a reminder: be careful where you step, look before diving, and swim with your eyes open.
The most common marine parasites (and what to do in case of a bite)
Let me introduce you to the most common causes of these purple warning signs.
1. Jellyfish (Most common)
Jellyfish are found in oceans around the world. Their tentacles contain nematocysts (stinging cells) which discharge on contact.
Symptoms of a jellyfish sting:
Immediate burning pain
Red raised marks (often arranged in the shape of a “whip”)
itching, swelling, numbness
Serious reactions: difficulty breathing, chest pain, muscle cramps (rare, but seek emergency medical attention).
What to do
