This work presents a circular polarized antenna used to increase the communication distance between small unmanned ships on the sea and the control station on land. Compared with popular commercial linear polarized antennas such as monopoles, the proposed antenna can effectively resist destructive interference caused by sea reflection, especially for small unmanned boats whose antennas are very close to the sea. The field test shows that the designed antenna equipped at the control station on land can achieve a longer communication distance than the antenna in the commonly used commercial wireless remote control system.