To assess the influence of ship-bank interactions on the course keeping ability of ships, Planar Motion Mechanism (PMM) tests on a scale model of the KVLCC2 tanker were conducted in a circulating water channel (CWC) at different ship-bank distances and speeds. To characterize the asymmetric hydrodynamic features, the asymmetric hydrodynamic derivatives are defined and are measured by the straight towing test with off-centerline displacements. The change in the linear hydrodynamic derivatives due to ship-bank interactions is discussed. The state-space equations are derived from the linear equations of maneuvering motion, which include the asymmetric hydrodynamic derivatives. The Linear Quadratic Regulator (LQR) is adopted to provide the rudder angle and the variation in forward speed during the course keeping process. The simulation results with varying ship-bank separations show that the LQR is more suitable than the classical proportional-integral-derivative (PID) controller for the course keeping of the KVLCC2 in the scenario discussed.