Abstract: The manoeuvrability of large ships is generally undesirable at their design speed, resulting in continuous risks to ship navigation safety. Meanwhile, the development of intelligent and unmanned ship design and construction brings stricter technical requirements for the safe realisation of autonomous ship navigation due to the inherent weakness in the manoeuvrability of large ships. To improve the braking performance of existing ships, the study proposes the installation of a pair of spoiler fins, the braking performance of which is investigated using real-scale CFD flow resistance analyses. Furthermore, the braking effects are simulated. The study shows that equipping large ships with properly designed spoiler fins can significantly improve their deceleration and steering performance, thereby promoting higher ship manoeuvrability and navigation safety.