Abstract: Underwater Sensor Networks(UWSNs) are remarkably different from land-based sensor networks,so the routing protocols for wireless sensor networks is not suitable for UWSN.To fit for the characteristics of underwater environments,a new routing protocol is studied.The proposed protocol is scalable and energy efficient.Simulations show that for underwater networks with no very large node mobility,the present protocol can effectively accomplish the goals of energy efficiency,high success of data delivery and low end-to-end delay.