What is the equivalent of LAT in US terminology?

The equivalent of LAT, or Lowest Astronomical Tide, in US terminology is indeed Mean Lower Low Water. LAT is defined as the lowest tide that can be expected to occur under average meteorological conditions and is used as a baseline for tidal measurements and navigation.

In the US, Mean Lower Low Water represents the average of the lower low water heights of each tidal day over the prescribed 19-year National Tidal Datum Epoch. This metric serves a similar purpose, providing a standard reference point for nautical charts and ensuring consistency in nautical navigation and hydrographic surveying.

Using Mean Lower Low Water as a reference point simplifies calculations related to tidal levels, as it accounts for the various fluctuations in tides due to climatic and geographical factors. This standard effectively translates the characteristics of LAT into a terminology commonly utilized in the United States, facilitating clearer communication and effective navigation practices.