Some important aspects of communication in underwater are neighbor selection, forwarding process (function) and holding time calculation. In order to predict the forwarding behaviour in network and its impact on holding time of nodes, it is convenient to have knowledge of domain and range of the forwarding functions. We have done comprehensive analysis on the respective forwarding functions defined in . The upper and lower bounds on the affecting metrics are given in Table 1. If the deepest layer of network is considered as reference level, hi = Dmax−Di gives the information about the height of node.