Mars’ controversial hypothesized ocean shorelines have been found to deviate significantly from an expected equipotential surface. While multiple different deformation models have been proposed to explain the wide range of elevations, here we show that the historical locations used in the literature and in these models varies widely. We find that the most commonly used version of the Arabia Level does not follow the originally described contact and can deviate laterally by ~500 km in Deuteronilus Mensae. A meta-analysis of the different shapefiles used for the Arabia Level shows that, globally, the location of putative shoreline varies by an average of 360 km and up to 1350 km along the topographic dichotomy. This leads to mean elevations of the level that vary by up to 1.7 km between different shapefiles, and topographic ranges within each shapefile ranging from 3.0 to 8.7 km. The younger Deuteronilus Level has less variation as it largely follows a formal contact (the Vastitas Borealis Formation) within the relatively flat northern plains. Given the high variance in position (spatial and topographic) of the levels, the use of such shapefiles and conclusions based on them are potentially problematic.