In this parer, the effects of a skeg, rudder and stern hull form on the manoeuvrability of a container carrier with small length to draft ratio have been investigated through a series of model test. Rudder open water tests and PMM tests were carried out with varying rudder area, afterbody appendages and stern hull form to investigate their effects on the manoeuvrability. The MMG model developed in Japan was used for the manoeuvring simulation with experimentally obtained hydrodynamic coefficients. The result showed that the effects by the variation of stern profile and the skeg below stern bulb are much larger than those by any other types of appendages in improving directional stability of the vessel.