Pol Lt Suphon Muangkhai, Deputy Investigator at Sakhu Police Station, received a report of the incident at about 6:30pm and coordinated with rescue workers and relevant officials to investigate.
According to initial reports, the unidentified man had been swimming off Nai Thon Beach in Moo 4, Sakhu, when he was pulled out by strong currents and large waves.
Lifeguards stationed at the beach attempted to rescue the man but were unable to reach him due to rough sea conditions, with waves reported to be more than two metres high.
Authorities launched a search operation in the area but were unable to locate the man before nightfall. The search was temporarily suspended at about 7pm and was expected to resume later.
Officials have again warned residents and tourists to avoid swimming during the southwest monsoon season, particularly at beaches displaying red warning flags, as strong waves and rip currents can pose serious dangers.