In the first report, the method to solve nonlinear optimal control problems of ship maneuvering motions is discussed. In this paper, the above theory is extended to the formulations under disturbances from the environment, such as wind and tidal current. Some examples of optimal solutions under some environmental disturbances are shown, and how to operate ship under such conditions is discussed. Then, the mathematical models of actual hardware devices, such as steering gear, CPP and side thruster, are presented under considerations of some limitations of their performances, and some new response functions and constraints functions to take account of the limitations are proposed. Then, the practical techniques are discussed for the use of the proposed method presented here for the purpose of automatically controlling an actual ship. Using a small training ship, sea trial tests are carried out to confirm the perfomance of the proposed controller. The results show the good performance with less feedback informations than conventional one.