1. A computer implemented method for determining if a contact in change detection side scan sonar imagery matches a previously found contact in the historical side scan sonar imagery of the same geospatial location, the historical side scan sonar imagery being in area-based tile format, the method comprising the steps of: for each contact in the change detection sonar imagery, finding contacts in the historical side scan sonar data in a region of uncertainty generated around the change detection sonar contact, and identifying the found historical contacts as a possible match; and if no historical contact falls within the region of uncertainty, returning all historical contacts that have with an uncertainty region that overlaps the uncertainty region of the change detection sonar contact, and identifying the returned historical contacts as possible matches.