Global sedimentary thickness (isopach) maps show their distribution on continents and in oceans. Underlying numbers provide volume and average thickness estimates. Of particular interest are thick accumulations on continental margins. For some diluvialists, they represent deposition during the Recessive Stage of the Flood, reinforcing a high post-Flood boundary. A Flood Regression Model proposes that the post-Flood boundary is a time-transgressive geomorphological boundary that links upstream erosion to downstream transport and deposition.