WHAT IS MLLW AND HOW DO I USE IT?
Mean Lower Low Water is a hydrographic datum and is dependent on locality. Since tidal regimes vary with river stages, weather, prevailing winds, currents, etc., the relation of MLLW to NAVD88 changes from place to place. MLLW is commonly associated with Mean Low Gulf (MLG), and is used for dredging in navigable waters.