A transmitting antenna operated on the naval vessels can be easily excited by exogenous disturbances such as tidal wave and impact. Gimbal system that supports the antenna needs the controller to maintain the robust performance against various modeling uncertainties and disturbance. PI controller, however, cannot guarantee the reasonable robust performance under these kinds of severe conditions. Thus a robust $H_{infty}$ control scheme is recommended to ensure a specified dynamic response under heavy operating conditions. Gimbal system is simplified as two degree of freedom model that ignores coordinate co-relations of each direction and hydraulic system is modelled linearly. The simulation and experimental results of $H_{infty}$ controller proposed in this paper showed the better responses and stability than those of PI controller.