This paper presents a motion planning, guidance, and control system for an autonomous surface vessel in a practical maritime environment. The motion planning algorithm is based on the angle-guidance fast-marching square method (AFMS), and the guidance system is based on the line-of-sight (LOS) trajectory tracking algorithm. To validate the motion planning algorithm, numerical simulations were carried out to compute the optimal path in a static environment including various obstacles. The guidance and control system were tested with an autonomous surface vehicle (ASV) tracking a pre-established trajectory including static obstacles. The autonomous surface vehicle is a self-propelled scaled ship model of 2.5 m equipped with sensors and actuators, inertial measurement unit (IMU), global positioning system (GPS), propulsion direct current (DC) motors, and wireless communication. From the experiments and numerical simulations, a good agreement was found.