Sojisuporn (2010) studied the seasonal variations in the surface water currents within the Gulf of Thailand using the temperature and salinity data derived from the world ocean database, the monthly dynamic heights anomaly from TOPEX/Poseidon and the ERS-2 altimetry data, during 1995-2001. The mean geostrophic current showed a strong southwestward flow of the South China Sea water along the gulf entrance. Counter-clockwise eddies occurred in the inner gulf and the western side of the gulf entrance. Seasonal geostrophic currents showed a basin-wide counter-clockwise circulation during the SW monsoon season and a clockwise circulation during the NE monsoon season.