VDatum stands for Vertical Datum Transformation, an innovative and evolving software tool under development by NOAA's National Ocean Service. Free to the public, VDatum's primary purpose is to convert elevation data from various sources into a common reference system.

A common reference system is important because irregularities can occur when maps and charts are created from different data sources. In a coastal area, for example, a shift in elevation on a gently sloping beach may change the overall depiction of the shoreline or results of inundation mapping.

VDatum's capabilities to transform and fuse diverse elevation data benefits coastal applications including inundation modeling (e.g., storm surge, tsunami, sea level rise impacts), ecosystem management and coastal planning, hydrographic surveying using Kinematic GPS for vertical referencing, and shoreline delineation from lidar data.

VDatum coverage is complete in all coastal regions of the continental U.S. (including the Great Lakes), Puerto Rico, and the U.S. Virgin Islands. A Southeast Alaska regional model was added in 2019, and future development of coverage for Hawaii, Alaska, and the Pacific territories will commence once foundational geodetic and tidal data are established to allow for valid model construction.

In addition, the current models are being revisited to include additional foundational geodetic and tidal data acquired that will assist in improving transformational components of the VDatum models, assist in refining and validating the uncertainty associated with models, and to support a wider range of applications. The goal is to develop a VDatum utility throughout the country that will foster more effective sharing of elevation data and, eventually, to link such data through national databases.