Abstract—In this paper, a trade-off between the energy consumption and network lifetime is considered. This paper proposes an optimal routing protocol called Energy Dynamic Adaptive Routing (EDAR) protocol. The DAR protocol maintains a tradeoff between the reliability or packet delivery ratio (PDR) of sensor nodes and Bit Error Ratio (BER) using optimal dynamic adaptive routing approach. The proposed approach operates on three different phases, namely, initialization, dynamic routing and transmission. During initial phase, all the nodes in the UWSN share location and residual energy information among all the nodes in the network. During dynamic routing phase, an optimal Directed Acyclic Graph (DAG) based route selection is exploited to select the neighbor and successor nodes. This facilitates the successive routing to transmit the packets from one node to another. Here, the cost function with directed acyclic graph is utilized for better transmission of packets. The experimental results show that proposed method encounters the issues raised in conventional protocol and improves the reliability of packets with higher BER.