What does Mean Lower Low Water (MLLW) represent?

Mean Lower Low Water (MLLW) represents the average height of the lowest of the two daily low tides over a significant period, typically 19 years. This tidal reference point is crucial for various nautical and coastal applications, particularly for charting and navigation purposes. MLLW provides a consistent baseline from which mariners can assess water depth and ensure safe passage in varying tidal conditions.

When assessing the context of MLLW, it helps summarize the relationship between high and low tides and establishes a standard for measuring shallow waters and potential hazards. Understanding MLLW is essential for ensuring that vessels will not encounter submerged dangers at low tide and for determining the appropriate tides for docking and undocking vessels.