City & County of Honolulu sign
Jellyfish warning
WH staff
Many come to Hawaii to enjoy the beaches, but once a month, another kind of visitor can make going into the water painful. Morever, visitors of the human kind can't spot these oceanfaring stingers.
Box jellyfish measure a mere 1 to 2 inches long, but have tentacles that stretch about a foot. They are nearly invisible in water, and their painful sting can be lethal if untreated, causing those who are allergic to go into anaphylactic shock. The painful stings can be relieved by using an ice pack or immersing the wound in warm water.
The jellyfish typically come near close to shore to spawn about 10 days after a full moon.
Do not touch beached jellyfish, as they are still toxic.
