Autopilot control makes a system go to the expected target trajectory. It does not replace the human operator's role but only assists the part of the system control operator. Autopilot control systems contribute to reducing human resources in performing tasks to realize higher reliability, observation, and supervision. Therefore, this study aimed to design an autopilot control system using GPS, compass, and ultrasonic sensors. It used a prototype ship weighing 1.7 kg, with a length, width, and height of 90 cm, 20 cm, 10 cm, respectively. Furthermore, the study tested the prototypes under calm water conditions without extreme external factors. The ATMega 2560 microcontroller was used as an electronic circuit controller-GPS sensor for latitude and longitude coordinates. The results showed that ultrasonic sensors detect objects, while the compass sensor moves the steering gear and rudder to maintain the ship's direction. Therefore, the ship could automatically avoid objects and navigate the target trajectory.