Details of the rare spectacle were realeased by the Foreign Office, Government Public Relations Department last week.
His Majesty King Maha Vajiralongkorn Bodindradebayavarangkun, accompanied by Queen Suthida Bajirasudhabimalalakshana, will board the royal barges at 1530, Thursday 24 October, for a 45-minute voyage along the Chao Phraya River that flows through the inner city.
Their Majesties the King and Queen will embark on the Royal Barge Suphannahong at the Wasukri Pier and disembark at the Ratchaworadit Pier.
The trip will cover 3.4km and consist of 52 ceremonial barges, including four royal barges; the Suphannahong, or Golden Swan, the Anantanakkara, or multi-headed Naga, the Anekkachatphutchong, or innumerable Naga figures, and the Narai Song Suban King Rama IX.
About 2,300 oarsmen will row the barges that are arranged into five groupings. Rhythmic barge-rowing songs are part of this ceremonial water borne procession, which is a rare spectacle, arranged on special occasions only.
The Royal Thai Government has extended an invitation to the general public to witness this historical event and has designated various sites along the banks of the Chao Phraya River as viewing locations which can accommodate up to 10,700 people.
The viewing locations
Santichai Prakan Park (1,500 people), Thammasart University (1,800 people), Nagaraphirom Park (2,300 people), Siriraj Hospital (100 people) King Bhumibol's 72nd Birthday Anniversary Park (1,000 people), Under the Rama VIII Bridge, Thon Buri (4,000 people)
Six temples on both sides of the Chao Phraya River will hold a Buddhist chanting ceremony in honour of Their Majesties.
They are Wat Rachathiwat, Ratchaworawihan, Wat Thewarat Kunchorn Worawiharn, Wat Sam Phraya, Wat Bowon Mongkhon, Wat Karuhabodee, and Wat Rakhang Kositaram. Each temple will begin the chanting ceremony when the Royal Barge is approaching and conclude when the procession has passed by.
The ancient procession was revived by the late King Bhumibol Adulyadej in 1960 after a lapse of several decades and took place at the end of Buddhist Lent, with robes presented to Buddhist monks as part of the event. However, there will be no presentation of Kathin robes in the Royal Kathin Ceremony at Wat Arun on this occasion.