Rescuers plucked four survivors from the water after the accident at the reservoir of Ratchaprapa dam in Ban Ta Khun district of Surat Thani province. One of them was the Thai boat operator, identified as Adipong Wichiankaew, and three others were foreign tourists, who were not immediately identified.

The Ratchaprapa dam is a tourist attraction inside the Khao Sok National Park.

Eyewitnesses said four foreign tourists hired the long-tailed boat operated by Adipong to take them out onto the lake for fishing and sightseeing. The boat capsized after hitting a floating tree trunk.

National park officials went out in a speed boat on a search and rescue mission but had still not found the missing tourist as evening fell.