An assumption of steady-state is a common basis for deep ocean circulation theory and observational strategies. We use GO-SHIP’s Easy Ocean uniformly gridded CTD data from repeat hydrographic sections to test this assumption. In particular, we ask: for what regions of the world ocean is there evidence that the planetary scale deep geostrophic shear and potential vorticity fields, related to potential density gradients, are in quasi steady-state over the past forty years? We find that away from boundary currents, planetary-scale potential density gradients in most parts of the deep ocean are stable from occupation to occupation, to within approximately 15% estimated standard error (lower in many parts of the global ocean interior), with higher variability in a few expected regions and for shorter sections.