There is a demand for the safety, health and environment of crews, and as a result, stricter design standards for ships exhaust pipe to control pollution is necessary. In the present study, the exhaust-smoke flow of anchor handling tug supply vessel was investigated using the computational fluid dynamics (CFD). To verify the computational methods, the turbulent shear-layer mixing flow was simulated and validated against experimental data. The exhaust-smoke flow was simulated for various wind speeds and directions with engine load of 10% NCR, providing valuable information for suitable exhaust pipe design.