Mean High Water averages all the highs recorded through the tidal datum epoch, counting both the higher and the lower high on mixed-tide coasts. US nautical charts show the mean high water line as the shoreline, and in many coastal states it separates private upland from public tidelands. Its partner, Mean Low Water, averages all low waters in the same way.
Survey the mean high water line along the parcel, the title company needs the MHW boundary.
Also heard as
- mean high water
Related terms
MHHW
Mean Higher High Water: the average height of the higher of each day's two high waters over the datum epoch.
MLLW
Mean Lower Low Water: the average height of the lower of each day's two low waters, used as chart datum in the United States.
Tidal datum
A local zero for heights, computed by averaging one stage of the tide, such as high or low water, across many years.
MSL
Mean Sea Level: the plain average of a station's hourly water levels across the tidal datum epoch.