Wind propulsion systems (WPS) are one of the most promising technologies for ship propulsion that can radically reduce greenhouse gas emissions. However, attention must be paid to the additional transversal forces and yaw moments connected to a wind propulsion system, as it can affect the manoeuvring and seakeeping performance of a ship. This paper demonstrates how time-domain simulations can be utilised to assess the manoeuvrability of a wind powered vessel to support the decision making, from the early design stage, all the way to testing the control systems, design of Human Machine Interface (HMI) and developing crew guidelines and training. The manoeuvre simulations are carried out with SSPA’s six degree of freedom inhouse code, SEAMAN-Winds. We present firstly a validation against manoeuvring model tests of a wind powered ship, where the wind propulsion units are represented by pulling fans. VPP calculations, which are commonly used in the early design phase, can predict the rudder angle required to balance the side force and yaw moment from the wind propulsion system. However, such steady-state computations provide no information on how robust this balance is when dynamic effects are present (e.g., wind gusts) and whether the balance can be regained if it has been momentarily lost. Therefore, time-domain simulations are shown to be useful to assess whether a ship can sail safely close to the limits of its VPP polars. Furthermore, it is demonstrated how mariners operating a real-time manoeuvre simulation tool can be utilised to increase the proof-of-concept, assess the HMI design, and for crew training.