NAVD 88

Recreation planners, GIS teams, and anglers comparing today's stage to a topo contour all need the same vertical reference. NAVD 88 is the label you will see on newer benchmarks, many LIDAR-derived surfaces, and an increasing share of inland water products.

When a neighbor quotes a Thurmond elevation in NGVD 29 and your app shows NAVD 88, you are not necessarily looking at different water—you may be looking at different zeros.

NAVD 88 replaced NGVD 29 as the preferred national vertical datum for many applications after the 1988 adjustment. Heights are orthometric: they follow Earth's gravity field through a geoid model, not a single tide gauge reading.

Related terms: Datum · NGVD 29 · MSL · Elevation reference · Gauge