Mean Lower Low Water

What is Mean Lower Low Water?

Mean Lower Low Water meaning (MLLW) – A tidal datum. The average of the lower low water height of each tidal day observed over the National Tidal Datum Epoch. For stations with shorter series, simultaneous observational comparisons are made with a control tide station in order to derive the equivalent datum of the National Tidal Datum Epoch.

 

reference: National Weather Service Glossary