In the past, we called Loi Krathong as Chong Pa Rieng- floating lantern of royal ceremony. It is a Brahman festival to worship Gods- Siva, Vishnu, and Brahma. When Thai people adopted Buddhism, they adapted this ceremony to honor the Buddhas cremated bone- the original Buddha at the second heaven ruler. They floated lantern to worship the foot-print of the Buddha on Nammathanati River beach in India