Join Jeff for a discussion of the various types of vertical datums of the National Spatial Reference System (NSRS), targeted for the floodplain manager, but great for anyone who works with 3D data analysis. We will review terminology, some technical history of the superseded vertical datum NGVD29, how NAVD88 is different, and the forthcoming new datum NAPGD2022. Vertical datum transformations (aka conversions), and tools available from NGS to do that, will be explained.