The Webb-Pearman-Leuning (WPL) formula is used to minimize the overestimate CO₂ flux by open-path gas analyzer and eddy covariance methods. However, its effectiveness for tropical coastal waters with high air water vapor content requires investigation. This paper assesses the WPL correction on CO₂ flux measurement over the tropical coastal water using three calculation methods: standard (including WPL and other correction methods), raw, and WPL. The results showed that the standard method yielded CO₂ flux of –0.10 µmol m^–2 s^–1, which is 60% lower than the raw. The WPL-CO₂ flux (–0.07 µmol m^–2 s^–1) is also lower than the raw (–0.25 µmol m^–2 s^–1) by 0.17 µmol m^–2 s^–1. The WPL formula serves its purpose in minimizing the CO₂ flux overestimation but uses caution with the formula as it can change positive-negative flux signs, especially with temperature and water vapor corrections.