The ferry, licensed to carry 150 passengers, was carrying 200 people from Lan Island to Pattaya, mainland Thailand, when it capsized Sunday at about 5:30 p.m., killing six people and injuring 18 others, the Bangkok Post reported.
Later Sunday, ferry captain Saman Kwanmuang, 42, turned himself into police and admitted to taking drugs before going to work, said Katcha Tatusatra, Chon Buri province police chief. Saman told police that the ferry wandered off course and hit some rocks, causing the vessel to capsize.
Saman said that he did not immediately alert passengers because he did not want to start a panic, however, when the bottom deck of the two-deck ferry began to fill with water, passengers panicked, as there were not enough life jackets for everyone on board, Katcha said.
Among the dead were three foreigners and three Thais, the Department of Disaster Prevention and Mitigation said Monday.
The injured were taken to local hospitals.