Tide Levels

[Happydrv]

How do mean low low water and mean high high water relate to the local reporting of tides as + or - from zero?

I've looked all over and can't find an explanation...

[StuM]

Meaning of the various levels such as MLLW are all detailed at


https://tidesandcurrents.noaa.gov/datum_options.html


"Zero" for tide tables depends on location. In much of the world, "zero" is lowest astronomical tide (LAT).
In the US it is generally MLLW


Or see this NOAA document:
https://tidesandcurrents.noaa.gov/pu...dal_datums.pdf