When a ship sailing at low speed passes a moored ship with a drift angle due to wind effect, the flow field around the ships is very different to the flow field without a drift angle and will cause larger hydrodynamic forces on the moored ship, compared with those without a drift angle. In this paper, a flow model in XBeach is applied to study the effects of a passing ship at low speed with various drift angles on the moored ship. This method is based on the non-hydrostatic shallow water equations. Simulations are carried out for a 12500 TEU container ship passing a moored Panamax ship by using XBeach. The water level depression, return current and hydrodynamic forces on the moored ship are obtained and compared with the measurement data. Then the results at positive and negative drift angles are compared with the results at zero drift angle, respectively. The influence of the drift angle on the passing ship effects is analyzed and the most serious situation for the moored ship, when the passing ship has different drift angles, is indicated. Finally, conclusions concerning the effects of a passing ship with a drift angle on a moored ship are drawn.
