The festival is celebrated over the span of three days and commemorates the end of the rainy season,[1] as well as the change in flow of the Tonlé Sap River.

[1][3] Some activities that take place at the festival are boat races along the Sisowath Quay riverfront, fireworks, and evening concerts.

After the boat race, large lanterns are released as part of the "Bondet Bratib" ceremony at 6:00 pm as representatives from national institutions pray for peace from Preah Mae Kongkea or the Goddess Ganga.

Cambodia also has a sacred river, the Tonle Sap, and festival goers communicate their love and respect for nature to the goddess through prayers of gratitude for her compassion.

It takes place at twelve minutes past midnight and involves a lantern lighting ceremony with prayers to Preah Purthisat, who invented the legend of the Moon rabbit.

The Og Ambok ceremony involves playing a group game where members must make each other laugh; whoever lasts the longest wins and decides the loser.

This was likely to commemorate the heroic victory of the Khmer navy, which liberated their land from the Cham troops of the Champa Kingdom in a boat battle on the Tonle Sap Lake.

[5] According to the record of Thach Pen alias "Piko (Pang Khat)" from the Khleang Province (Soc Trang), Kampuchea Krom (Southern Vietnam), in 1528 AD, King Ang Chan I ordered Ponhea Tat, the commander of the Khmer navy in the Bassac District of Kampuchea Krom, to prepare the Khmer army to defend the province of Preah Trapeang (Tra Vinh, Vietnam), which was under attack from the Đại Việt kingdom under Mạc Đăng Dung.

The naval boats were divided into three groups: After his victory, concurrent with the crowning of King Ang Chan I in 1529 AD, he celebrated the Bondet Bratib ceremony every year with candles at night to commemorate the victory over the Đại Việt and to give thanks to the goddess Ganga (Preah Mae Kongkea in Khmer language).

The Khmer people conduct this festival during the full moon of November in the belief that great merit and prosperity will be provided to the country.

The Khmer people believe that Bondet Bratib took place in the eighth century; the original name floating "Bay Sey" or Bondet "Bay Sey" (បាយសី) in the Chenla period, the original Khmer religion depicting the people before the Angkorian period celebrating the rituals.

It was first practice along the banks of the Mekong river delta during the time period when Shailendra dynasty of Java ruled Water Chenla.

LoyKantong are religious offerings for Hindu goddess Ganga to show gratitude and appreciation for the life giving waters of the Mekong river.

The ritual offerings are still practice during Bon Om Touk festival every year after the end of monsoon rain season.

The Khmer-Javanese compound word LoyKantong លយកន្ទោង /lɔɔy kɑntooŋ/ to make an offering to the spirits by floating small bowls made of leaves and filled with food, etc.

Og Ambok (Khmer: អកអំបុក, IPA: [ʔog ɑmboːk]) is a traditional flattened rice dish that forms part of the Bon Om Tuk ceremony.

Og Ambok remains a popular traditional dish and it is sold widely during the Bon Om Touk festival.

It is believed that in the reign of King Barom Reachea III he dreamed of Indra fighting with a demon in the Longvek fortress.

In the morning, he sent his officers to inspect the surrounding land in Banteay Longvek and found the site of a real lightning strike.

[26] For example, the Rigvedic hymn 1.32 dedicated to Indra reads: इन्द्रस्य नु वीर्याणि प्र वोचं यानि चकार प्रथमानि वज्री । अहन्नहिमन्वपस्ततर्द प्र वक्षणा अभिनत्पर्वतानाम् ॥१॥ अहन्नहिं पर्वते शिश्रियाणं त्वष्टास्मै वज्रं स्वर्यं ततक्ष। वाश्रा इव धेनवः स्यन्दमाना अञ्जः समुद्रमव जग्मुरापः ॥२॥ Let me tell you the manly deeds of Indra, which he first accomplished, bolt-weaponed, He slew the serpent, opened up waters, cleft in twain the belly of mountains,॥1॥ He slew the serpent on the mountain, with a heavenly bolt made by Tvastar, Like lowing cattle downward sped the waters, then flowed to the ocean.॥2॥[28] During the ceremony, four or five punchers are assigned to help and two or three rookers are in each group.

Cambodians usually set up an array of offerings in the form of fruits that are popular with rabbits, such as Ambok, banana, coconut, yam, sweet potato and drinks.

They light incense in front of their homes at night before gathering at pagodas at midnight for the third ceremony, Ak Ambok[31] where they remember the life of Pothisat the moon rabbit.

Once consumed, adults usually take a handful of ambok to feed it into the mouth of younger children as a sign of care and goodwill.

While holding their noses, children open their mouth and look at the Moon, usually making a wish, to remember the generosity of the altruistic rabbit as a model.

[33] After the Sampeah Preah Khae ceremony, devout Buddhists gather at a pagoda at midnight for the rites associated with Ak Ambok.

It is said that there was Asura, an ascetic named Vritra, who ruled over dragons and stopped all water from flooding, which caused drought across the region.

At that moment, a single strand of hair of the Ganges fell to the ground and it became the sea dragon or water-monster, Makara or Makor in Khmer, which was stronger than any other animal in the world.

[35] The Royal Water Festival, which lasts for three days, was recorded for the first time under the reign of King Norodom in 1873 and follows a precise ritual.

[39] Phnom Penh authorities came under fire in 2016 for sanitation, after videos of cleaning crews sweeping trash into the Tonle Sap incited anger on social media.