Underwater wireless sensor network (UWSN) is a cutting-edge wireless technology that has emerged as a significant field in modern communication, involving the deployment of tiny sensors with limited capabilities in deep-sea environments. UWSN finds applications in various domains. However, UWSNs pose many communication challenges such as limited bandwidth, significant ocean interference, high propagation delay, and dynamic topology. These challenges directly relate to the routing protocol (RP) of UWSNs. RP is crucial for maintaining connectivity, reliable data transmission and extending the operation of UWSNs. This paper devises an energy-efficient, localization-free routing protocol, called the Energy-efficient routing protocol in UWSNs (EERPUWSN). Experimental results indicate that EERPUWSN surpasses multiple conventional protocols in minimizing network delay while maintaining comparable or better energy efficiency and packet delivery ratios underwater environment.