This paper presents a solution to the trajectory-tracking control problem of an Autonomous Surface Vehicle (ASV) under the effect of sea waves. Worldwide, there has been increasing interest in the use of ASVs to execute missions of increasing complexity without direct supervision of human operators. A key-enabling element for the execution of such missions is the availability of advanced systems for motion control of ASVs. The problems of motion control can be roughly classified into three groups: i) point stabilization, where the goal is to stabilize a vehicle at a given target point with a desired orientation; ii) trajectory tracking, where the vehicle is required to track a time parameterized reference; and iii) path following, where the objective is for the vehicle to converge to and follow a desired geometric path, without an explicit timing law assigned to it. In some applications where it is critical for ASVs to follow the preplanning trajectory as closely as possible, the trajectory problem of ASVs becomes important.