In this thesis,a reliable and energy-efficient routing (RER) protocol is proposed for underwater sensor networks (UWSNs) to enhance communication reliability. In the route discovery phase of the proposed method,a node with the minimum packet transmission delay to the currentnode is selected as its nexthop node.After a route is established,other nodes in the network will also transmit packets to the sink through it, which greatly reduces the amount of time and energies expended to construct a new route. As a result, real-time
data willarrive atthe destination earlier,and the network lifetime will be extended. To handle the case of node failure on the established route,the proposed RER protocolincludes a route recovery scheme in which a new node will be selected instead of the failure node to continue the packet transmission. Through simulations, the proposed RER protocol is shown to outperform the traditional routing protocol in terms of average end-to-end delay, packet delivery ratio, and average energy consumption.