On ships using methanol as fuel, the vent mast of the methanol tank is a potential release point for methanol vapor, which may be released during navigation or bunkering operations. As a toxic substance, excessive inhalation of methanol can harm crew health. Classification rules require a minimum distance of 15 meters between the methanol vent mast and non-watertight openings in accommodation areas. Consequently, the vent mast is typically positioned away from accommodation areas during the design phase. However, some smaller vessels may be unable to meet this requirement due to layout constraints. Furthermore, the extent of the influence of methanol vapor released from the vent mast is affected by factors and conditions such as the release rate, ambient wind speed and direction, and the aerodynamic profile of the surrounding structure. Relying solely on the 15-meter spacing requirement is insufficient to determine whether a release from the vent mast during actual operation could lead to personnel exposure to toxic concentrations. Therefore, this study employs computational fluid dynamics (CFD) simulations to analyze gas dispersion from a methanol vent mast located at the bow of a methanol-fueled ship under different wind speeds. The research aims to investigate the extent of the methanol toxic zone and to verify that the hazardous area generated by the vent mast does not endanger crew health.