A great interest among researchers to establish Underwater Wireless Sensor Networks (UWSN) with mobile nodes have been created in recent past because of numerous potential applications in aquatic science. In comparison of radio communication, acoustic communication has lower bandwidth and larger propagation delay. This enacts additional restrictions on any localization algorithm. Existing range‐based approaches involve increased localization latency and error even with large deployment of anchor nodes. Some of the optimized localization techniques involve higher energy consumption and cost. In order to solve these issues, a hybrid optimized localization technique is proposed that can accurately localize mobile nodes in UWSN. In this algorithm, a fitness function is concluded based on the number of hops from the anchor node, Time of Arrival (ToA) distance estimation error and transmission delay. In comparison of existing localization techniques, proposed algorithm helps in reducing the energy consumption, localization error, localization delay and localization cost and experiment results proved the same.