Geodetic survey records for a meridional chain of first‐order leveling spanning 50 latitude degrees are available at the Defense Mapping Agency Topographic Center (DMATC) for the Pacific coast of South America. The coastal route from Talara, Peru, to Puerto Montt, Chile (37° of latitude or 4,100 kilometers of arc), has been analyzed to evaluate the accuracy of the leveling and to determine whether or not “mean water level” (MWL) has a slope relative to the equipotential surface passing through Talara. A provisional meridional, sea‐level profile is discussed in terms of the magnitudes of the different kinds of measurement uncertainties.