Navigation General · Tides
What does Mean Lower Low Water (MLLW) represent?
- AThe average height of all low waters at a given location
- BThe average height of the lower of the two daily low tides over a 19-year tidal epoch✓ Correct
- CThe lowest tide ever recorded at a location
- DThe average height between high water and low water
Explanation
MLLW is the average of the lower low waters observed over the National Tidal Datum Epoch (a 19-year period), used as the reference datum for chart soundings in US coastal waters. It is not the lowest possible tide, but the average of the lower low tides.
Authority: NOAA Tide Tables
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