The Mean Low Tide (or Mean Low Water) is the average height of all low tides in a given place, deriving from a long series of observations (NTDE) of all levels of low tide in that spot.

What is mean low water level?

mean low water: (MLW) - the average height of all low waters at a place over a 19-year period. ( IHO Dictionary, S-32, 5th Edition, 3147) lowest low water springs: an arbitrary level conforming to the lowest water level observed at a place at spring tides during a period of time shorter than 19 years. (

What is mean low low water?

Mean Lower Low Water. The average of the lower low water height of each tidal day observed over the National Tidal Datum Epoch. For stations with shorter series, comparison of simultaneous observations with a control tide station is made in order to derive the equivalent datum of the National Tidal Datum Epoch. LAT.