The 30-seat boat, Por Chokyothin, was carrying 23 tourists to view fireflies at night along the river when another passenger boat, Sor Sakcharoenporn, with no passenger on board crashed into it in front of Wat Bang Khae Yai in tambon Kwai Om, said Pol Maj Wattana Nuansridam, a duty officer at Amphawa police station, who was alerted around 8pm on Friday.