## 7 Results and Discussion
This is because of the enhanced efficiency of data transmission in larger payloads as they allow more data to be sent per packet, reducing the overall number of packets needed for transmission. Additionally, larger payloads reduce the ratio of packet overhead to the actual data transmitted. Also, higher node density and route selection based on neighboring nodes provide more robust networks with more available routes, which reduces the possibility of void regions. Figure 6f illustrates the number of dead nodes as payload (200 bytes to 500 bytes) and node density varied. The number of dead nodes decreases as node density increases. In sparse networks, nodes are more likely to deplete their energy rapidly, especially when transmitting larger-sized payloads such as 500 bytes, due to the longer distances required for communication and fewer available nodes. Larger payloads can lead to higher energy consumption, which can lead to a higher number of dead nodes prematurely. However, as node density increases, the network becomes more energy efficient and prolongs their network lifetime. Network Performance Comparative Analysis: This proposed research work provides a network performance comparison with some of the existing state-of-the-art routing protocols. The network performance of our proposed routing strategy, REOVA, is compared with DBR [28], EE-LCHR [38], EEDBR [48], and IBAS [52]. The network performance of our proposed routing protocol REOVA is compared with the routing protocols based on three performance metrics, e.g., energy consumption, packet delivery ratio, and end-to-end delay. The total number of considered nodes is 100 with a difference of 100 nodes to the maximum number of nodes of 800. The 3D underwater network boundaries are defined as 1000 m on each X, Y, and Z plane. Each node has an initial energy of 10,000 uJ, with the transmission mode power consumption, and it receives mode power consumption of 2 uJ and 0.5 uJ, respectively. The maximum transmission distance, the packet size, and simulations are defined as 250 m, 50 bytes, and 50, respectively. The simulation parameters are defined to ensure fair comparison as in [38]. Figure 7a illustrates the comparison of our proposed routing protocol with some existing routing protocols in terms of energy consumption (EC). The EC of our proposed protocol is much less than that of other routing protocols. DBR consumed the highest energy. The energy expenditure of EEDBR is much higher as compared to all the other routing protocols because data packets often either travel longer paths or repeatedly burden specific nodes, which leads to higher energy tax. The EE-LCHR used a residual energy-based cluster head rotation mechanism. However, its energy consumption is also higher than IBAS and the proposed scheme. The IBAS protocol election of a cluster head on the fitness function emphasized direct communication from the cluster head to the sink node and never considered the communication path quality and nearby node to preserve energy. Our proposed routing protocol is significantly efficient in terms of energy usage due to the proposed combination of strategic node deployment and the efficient selection of routing path based on residual energy, link quality, and neighboring cluster head node density, outperforming the other existing approaches. Figure 7b illustrates the comparison of our proposed routing protocol with some existent routing protocols in terms of packet delivery ratio. The node densities in all the routing protocols, which are considered for the comparison of PDR, are the decisive factor in successfully routing data packets to their destination. The DBR and EEDBR are slightly less reliable in routing data packets to their destination due to the frequent selection of similar nodes for routing packets. This could lead to the early demise of such nodes and create larger gaps between nodes, which can disrupt communication. Likewise, in EE-LCHR and IBAS, the node deployment is random, which may create some regions densely populated and others sparsely populated.