Narongsak, who formerly held the post of governor of the province of Chiang Rai, was widely recognised for his perseverance in helping the team and their coach escape the flooded cave.
The funeral is being held from Friday to Sunday at Wat Phra Si Mahathat in the Bang Khen neighbourhood, with Anupong Paochinda, Minister of Interior, presiding over the bathing rites.
The King also bestowed a royal wreath.
His family, relatives, and prominent figures attended the rites, among them Bangkok Governor Chadchart Sittipunt, who appeared visibly upset at Narongsak’s passing.
Chadchart later said that Narongsak had been his professional role model and expressed sadness over not having had the chance to work with him.
May he [Narongsak] rest in peace, Chadchart said.
One of the Royal Thai Navy SEALs involved in the rescue effort Thanadet Kittisuthiprem said that Narongsak was a kind person who took good care of the SEAL team during the operation.
Narongsak passed away from colon cancer at Siriraj Hospital in Bangkok at the age of 58.