The diver “was seen to have his regulator out of his mouth while underwater on the ocean bottom, in 15 meters of water” and after being retrieved at surface the emergency helicopter dropped a doctor to the Quicksilver helicopter pad. After an extended effort with no response, the diver was declared dead. He was a possible victim of the tiny, highly venomous Irukandji jellyfish. Two days before , on Wednesday morning ,two French tourists were pulled from the ocean within five minutes of each other after having fatal heart attacks while diving on the Great Barrier Reef. Irukandji jellyfish are the smallest and most venomous box jellyfish in the world and one of the most venomous creatures on Earth. They are five known species, known for causing symptoms collectively known as Irukandji syndrome from hours to weeks. Hypertension is also manifesting.