New Year's weekend vacationers were warned of waves up to 3 meters (10 feet) high lashing coastal areas on the Gulf of Thailand, the official Thai News Agency said Sunday.
The Tourism Authority of Thailand has urged revelers to closely monitor weather forecasts before heading for beaches in the southern region of the gulf, it said.
High waves were reported on beaches in the provinces of Surat Thani and Chumphon, both popular with Thai and foreign tourists.
Rescue workers are patrolling both land and sea areas to help tourists in the event of accidents, the agency said.
In neighboring Malaysia, the Meteorological Department warned of waves of up to 4.5 meters (15 feet) off the eastern coast of peninsular Malaysia and the Borneo states of Sabah and Sarawak.
The rough seas were expected to persist until Monday and would be accompanied by strong winds of 50-60 kilometers (31-37 miles) per hour, it said in a statement.
The conditions were dangerous to all shipping and ferry services, it said.