Underwater exploration is one of the areas of importance today because of the interest in the field of underwater archaeology where it is injurious for humans to materially visit a spot. These applications demand precise data collection. Underwater sensor networks (UWSN) are the network of autonomous sensor aided devices called sensor nodes deployed over a region of water for collaborative execution of the specific task. UWSNs are being widely studied and the networks enable collecting data from remotely deployed nodes under the water and transmit these data for processing at a server node residing in a terrestrial area. Sensor nodes use acoustic signals as wireless communication transmission medium that operates at low frequency. Acoustic signals are largely affected by underlying noises like the sound of aquatic animals, continuous drifting of nodes due to water movements, and noises of underwater vehicles like submarines. So data collection phase demands high energy. Since sensor nodes are battery-operated devices, protocols for wireless communication play a vital role in conserving energy for long network life. In this paper, the performance of two popular routing algorithms Vector-Based Forwarding (VBF) and Depth Based Routing Protocols (DBR) is evaluated and analyzed that support increasing the longevity of the deployed network. The performance is analyzed with respect to Packet Delivery Fraction (PDF). Simulation results verify that DBR gives better performance as compared to VBF protocol when the number of sink nodes is increased.