While it is extremely rare for swimmers and divers in Thailand to be stung by jellyfish, we do ask that everyone planning to swim or dive, particularly in the south of the country, to be aware that there may be jellyfish present. Do not swim if there are warning signs and always make sure of the location of the nearest First Aid centre before bathing.
Several species of jellyfish, mostly harmless, can be found seasonally in Thailand. However, Box Jellyfish are initially found off the beaches of Ko Lanta and Hat Nopparatthara – Mu Ko Phi Phi National Marine Park off Krabi province, Nam Bo Bay in Phuket province and often off Hua Hin and Cha-am Beaches in Phetchaburi province, as well as Ko Tao in Chumphon province, Ko Samui, and Ko Pha Ngan in Surat Thani province