This paper investigates the influence of ship model size on manoeuvring hydrodynamic coefficients utilising a Reynolds Averaged Navier–Stokes solver. The hydrodynamic forces and yaw moment on a KRISO Very Large Crude Carrier (KVLCC2) model have been predicted for a static drift and a pure sway test and validated against benchmark model scale test data. Good correlation was observed between the measured and predicted force and moment results indicating adequate numerical modelling. On validating the numerical prediction technique, a set of systematic simulations on different size KVLCC2 ship models and the full scale vessel has been carried out for pure sway, static drift and pure yaw tests to study the scale effects on the hydrodynamic forces and moment obtained from the captive manoeuvres. It is seen from the simulations that the full scale KVLCC2 vessel had a relatively smaller turbulence wake region after the hull when compared with model scale conditions. From the obtained force and moment results, scale effects were evident in the surge and sway forces but found to be less influential in the yaw moment for the cases tested.