Underwater networks consist of a variable number of sensors and vehicles that are deployed to perform collaborative monitoring tasks over a given area. Underwater Acoustic Networks (UANs) are very unique and can be deployed for commercial and military applications. The research of UANs attracts increasing attention in recent years. Here node deployment and localization performed for 3-D environment. Implemented different deployment scheme such as random deployment, cube deployment and regular tetrahedron deployment scheme. Among the various deployment strategy regular tetrahedron deployment scheme outperformed. Their performance have been evaluated in terms of reducing localization error and increasing localization ratio with not changing the average number of neighboring anchor nodes and maintained maximum network connectivity. For this estimation of the performance which is implemented by received signal strength indicator (RSSI) technique which utilizes the relationship between the transmitted signal power and received signal power. Based on the multilateration method can estimate the coordinates of the ordinary nodes with the known location of anchor nodes. The performance of deployment scheme computed, maximum localization ratio represented the localization of more number of ordinary nodes.