Tidal datum information
The vertical reference level for each standard port is the port datum. Since 1994, this datum was set to the lowest astronomical tide (LAT) at Queensland ports. To define this datum a tide gauge benchmark (TGBM) is established. The height of this benchmark, relative to LAT, is then used to define the port datum onsite.
The vertical distance between the TGBM and LAT is given in the standard port datum below.
The official tide predictions for Queensland standard ports are given as heights above the port datum (LAT). To account for changes in sea level, an adjustment is made to the mean sea level estimate. This mean sea level is used as the basis for tide predictions.