Ship-bank interactions induce a suction force and a yaw moment to influence the ships course keeping performance, known as the bank effect.To assess the forces, the systematic captive model test program that used the planar motion mechanism (PMM) system in a circulating water channel (CWC) was first carried out in China.A scale model of the KVLCC2 Moeri tanker was selected to conduct the tests at different ship-bank distances, water depths and forward speeds.To investigate the accuracy of the CWC experimental technology in measuring the ship-bank interaction forces, the uncertainty analysis is performed according to the ITTC recommended procedures and guidelines 7.5-02:06-04.The systematic bias is categorized in reference to the empirical formulae of ship-bank interaction forces, so new error sources such as ship-bank distance and water depth can be included in the uncertainty analysis.It is confirmed that the bias caused by water depth makes a major contribution to the uncertainties of ship-bank interaction forces.The reported uncertainty analysis results also show the reliability of the CWC tests to study the ship manoeuvring hydrodynamics in restricted water condition.