The case study focuses on the interactional mechanisms through which online collaborative teams co-construct a shared understanding of an analytical geometry problem by using dynamic geometry representations. The collaborative study consisted of an assignment on which the learners worked together in groups to solve a ship navigation problem as described in the Virtual Math Teams (VMT) environment. In this paper, a single group's problem solving activities were qualitatively analyzed to understand how they achieved a sense of joint perception of their shared workspace as a navigational chart which encodes the physical relationships between landmarks in the form of angle and distance measures. The analysis of the excerpts indicated that the initial struggles and their resolution in interaction as participants mastered the use of dynamic features in their shared workspace helped them gradually develop a shared understanding of the key spatial relationships among landmarks encoded in the 2D chart.