The lockdown is effective immediately until the situation is resolved, said Chonburi governor Phakthorn Thianchai, in his capacity as chairman of the provincial Communicable Diseases Committee.
The move comes after the Covid-19 outbreak in neighbouring coastal districts including Sri Racha has continued to spread. To stop transmission of the virus, Koh Si Chang has been completely locked down.
The Chonburi marine department will impose measures for boat operators while the sheriff of Koh Si Chang has been tasked with policing the lockdown.