What is the datum used by mariners related to low tide known as?

The datum used by mariners related to low tide is known as Chart Datum. This reference point is critical for navigators, as it provides a reliable baseline to which depth soundings and other navigational data are related on nautical charts. Chart Datum typically corresponds to the lowest astronomical tide, which means it establishes the minimum depth of water that can be expected in a given area. This ensures that mariners can assess safe navigation routes, avoid grounding, and plan for tidal variations.

Understanding Chart Datum is essential in hydrographic surveying and navigation, as it helps to communicate underwater features accurately and informs the necessary precautions when navigating through shallow waters. This datum can vary between regions, emphasizing the importance of using the correct Chart Datum pertinent to a specific area to ensure mariners are working with accurate data.