In this paper, the authors propose a maritime communication system based on the Ad-hoc technology. The network architecture, radio interface, path loss model, accessing control, power control and routing algorithm used in the proposed system are also described in this paper. The routing algorithm used in the system is AOMDV [1]. A power control mechanism is integrated into the routing protocol and data transmission, thus the energy consumption in the system is minimized. Simulation results show that the proposed power control mechanism achieves a high performance by saving 10 percent energy consumption in average compared to previous approaches.