We consider the problem of interactive source coding in a sensor network, where the user can freely choose the source (sensor) he wants to observe. Such an interactive navigation scheme must (i) take into account the possible correlation between the sources (ii) encode the data off-line and therefore independently of any navigation and finally (iii) transmit without any delay upon request of a source. We derive the information theoretical limits in terms of rate and storage of such interactive source coding scheme. Moreover we show a counterintuitive result: freely choosing its source at the receiver incurs a loss in terms of storage only and not in the transmission rate. This corrects a result of Draper et al.\cite{Draper07} which claims otherwise. Finally, as an application, we consider the problem of video compression with free viewpoint interactivity and derive the gap between the optimal scheme proposed here and interactive schemes proposed so far.