Chart Datum - Mean Lower Low Water

Mean Lower Low Water

The United States' National Oceanic and Atmospheric Administration uses mean lower low water (MLLW), which is the average height of the lowest tide recorded at a tide station each day during the recording period. MLLW is only a mean, so some tidal levels may be negative relative to MLLW.

Read more about this topic:  Chart Datum

Famous quotes containing the word water:

    The point of the dragonfly’s terrible lip, the giant water bug, birdsong, or the beautiful dazzle and flash of sunlighted minnows, is not that it all fits together like clockwork--for it doesn’t ... but that it all flows so freely wild, like the creek, that it all surges in such a free, finged tangle. Freedom is the world’s water and weather, the world’s nourishment freely given, its soil and sap: and the creator loves pizzazz.
    Annie Dillard (b. 1945)