<p>Rescue robots operated in disasters such as earthquake aedeveloped in researchers. Recently, developments of robots for exterm environmental work such as rescue, seafloor exploration and so on has been carried out. In this study, we focused on Hovering type underwater robot. Hovering type under water robot has a high fixed point observation ability and a high degree of freedom and is excellent in responding to various environments. In our lab, studying two robots which are USO(Unmanned Swimming Object) using the flight mechanism of drones and underwater robot using vector thruster mechanism. In this paper, a thruster sysytem for an underwater robot were developed.</p>