In March 2019, the Underwater Archaeology Division, Fine Arts Department, Thailand, discovered the remains of boat timbers kept by a villager in a palm plantation in Chaiya sub-district, Surat Thani Province, Thailand. The wood-crafting techniques demonstrated by the preserved wood remains showed that the archaeological remains were from an ancient lashed-lug boat – a technique common for manufacturing vessels that was widespread in Southeast Asia. Three organic samples taken from the boat were sent for AMS radiocarbon dating. The results of the chronometric dating demonstrated that the boat was manufactured during the  9th century CE. This article will describe and depict the key characteristics and features of the boat, and explores how this vessel provides new insights into the ancient maritime trade of Southeast Asia during the 9th century CE.