− This paper addresses the combined problem of trajectory planning and tracking control for underactuated AUVs moving on the horizontal plane. A reference feasible trajectory for the position and orientation of the AUV is planned so that it is consistent with vehicle dynamics. Using these reference values the dynamics of the vehicle is transformed to the error one. Partial state-feedback linearization, backstepping and non-linear damping techniques are utilized to stabilize the above system and force the tracking error to a neighborhood about zero that can be made arbitrarily small. Simulation results that validate the proposed tracking methodology are presented and discussed.