Underwater acoustic sensor networks (UASNs) are used to explore underwater environment, study aquatic life and gather data regarding geographical variations. Since the communication medium used in UASN is water, they are different from other networks. Major Challenges that affect data transmission include higher energy consumption, higher propagation delay and low bandwidth. The proposed method reduces the energy consumption of the network. Firstly the node forms a group of forwarding nodes based on fitness factor and density (i.e. no. of neighbor present around source node). Among the group of forwarding nodes, the node having maximum packet delivery ratio and highest energy is selected using fuzzy logic based relay selection (FLSR). As huge amount of energy is wasted during collisions among packets while transmission. Since the sensor nodes have restricted energy, the main challenge is to send packet till destination. Therefore to counter this problem, holding time is set for each of the group of relay nodes to avoid collisions. The simulations are performed in Aqua-sim and the results are compared with other protocols. © 2018 IEEE.