In cooperative robot teams, communications can speed up execution, reduce duplication, and prevent interference. Although many systems use explicit communications, persistent intra-team digital communications is not guaranteed. One approach to this challenge is to use implicit communication to infer state rather than using digital messages. We investigate using implicit communication in the form of observation to infer state to coordinate a robot team in a coverage task. We demonstrate how pruning and backtracking a search tree can improve multi-robot coverage. Experiments were conducted to compare team performance of a robot team using observation-based cooperation to one that uses explicit communications.