Network coding (NC) is a promising approach to efficiently enhance the robustness and recovery capacity in the Underwater acoustic sensor network (UWASN). However, the undesired transmission redundancy and additional resource limit the further development for NC with applications to the UWASN. Based on the analysis of intermediate nodes, a new approach called encoding anticipation mechanism for network coding (EANC) is proposed, by making network nodes adjust adaptively operation of NC on-off with its transmission capability (i.e. the tradeoff between the utility of packet innovativeness and communication capabilities with neighbor nodes). The simulation results demonstrate that this proposed method effectively reduces unnecessary coding operation and the expense of overall packet overhead, while realizing the transmission validity and reliability if specific node is set to be NC node. These merits make the EANC mechanism helpful in presenting better adaptability to the UWASN.