This paper introduces a vision-based dynamic positioning (DP) control system and develops a hardware-in-the-loop (HIL) platform to validate the performance of the controller applied to a work-class remotely operated vehicle (ROV). The proposed platform consists of three main parts: hardware, image processing part and controller. The hardware included a calibrated camera that was connected to a dedicated computer via USB 2.0. In the image processing part after pre-processing a circular Hough transform was used to detect and determine the position of the target in the image plane. Furthermore, this paper proposed a feedforward proportional-integral-derivative (PID) controller. To evaluate the performance of the proposed controller, two scenarios were implemented. In the first scenario, the target was considered stationary and a disturbance was applied to the ROV in the simulation environment. In the second scenario, the target object has moved along a rectangular path, and the objective was to stabilize the ROV at the desired points. In both scenarios, the reference signal was acquired by a calibrated camera from the target and sent to the controller. The results showed the desirable performance of the proposed controller.