Which of the following is a principle vertical datum in use?

The North American Vertical Datum of 1988 (NAVD88) is recognized as a primary vertical datum commonly used in North America for various applications, including engineering, mapping, and hydrography. NAVD88 provides a consistent reference for elevation measurements across the continent and is critical for various geospatial analyses.

This datum replaces the earlier National Geodetic Vertical Datum of 1929 (NGVD29) by providing updated and more accurate measurements based on enhanced methodologies, including the use of GPS technology and improved surveying techniques. NAVD88 establishes a zero reference point based on mean sea level at a specific location and enables users to determine elevations relative to this baseline across different geographic regions.

While other options mention various datums and systems, they either do not have the same level of recognition, or they are not specifically established vertical datums used in the same manner as NAVD88. For instance, the World Vertical Datum of 2000 is not commonly referenced in practice, GPS Vertical Datum is more about a method of acquiring vertical information rather than a formal datum, and the European Vertical Reference Frame 2000 pertains specifically to elevation on a European scale. Thus, NAVD88 stands out as the recognized and widely utilized vertical datum in North America.