Providing better communication in UWSNs and maximize the communication performance is challenging issue due to volatile characteristics of underwater environment. Radio signal cannot properly propagate in underwater, so there is need, such type of acoustic modem technology that can supports better data rates and reliable underwater wireless communications. Further, nodes mobility, 3-D spaces brings some critical challenges for the researcher to design new routing protocol for UWSNs, to handle the issues like high end to end delays, Propagation delay, as well as power constraints of the sensor nodes. Many routing algorithms have been proposed in last two decades and some of them provide better solution to handle such type of issues. In this paper, we proposed a novel routing protocol called Layer by layer Angle Based Flooding (L2-ABF.), to address the problem node swaying issue, end-to-end delays, and node energy consumption. In L2-ABF, every node can calculate its flooding angle to forward data packet to the next upper layer toward the surface sinks without using any explicit configuration and location information. The simulation results show that L2-ABF has some advantages over some existing flooding base techniques and can easily manage quick routing changes where node movements are frequent. © 2012 IEEE.