This document analyzes data transmission in underwater acoustic sensor networks for complex environments. It discusses the challenges posed by the underwater environment, including limited bandwidth, high propagation delays, and high bit error rates. It proposes a clustering-based routing protocol called EGRC that partitions the 3D environment into blocks and selects cluster heads based on residual energy and location to optimize energy efficiency and reliability of data transmission. Simulation results demonstrate that EGRC performs better than other protocols in terms of energy efficiency, reliability, and end-to-end delay. The protocol aims to improve network lifetime by reducing redundant data and optimizing energy usage across the entire network.