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 tide gauge benchmark (or best recovery mark where the tide gauge benchmark has been destroyed/disturbed/is unstable) and LAT is given in the Semidiurnal and diurnal tidal planes tables.

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.

Mean sea level used for the tidal predictions for 2023

An allowance of 2.4mm per year for sea level change has been made in the mean sea level (MSL) estimate. The allowance is calculated from the central date of the observation period to the central date of the prediction year. The heights are referred to Queensland Port Datum.

Place  Observation period Mean Sea Level
(MSL)
Gold Coast Seaway
Jan 1993 to Feb 1999
0.822
Brisbane Bar
Jan 1985 to Dec 2020
1.331 
Mooloolaba
Jan 1987 to Dec 2020
1.008 
Noosa Head
Dec 1970  to  Dec 1971
1.161 
Waddy Point (Fraser Island)
Oct 1976  to  Feb 1978 
1.191 
Urangan
Sep 1986  to  Dec 2020
2.143 
Bundaberg (Burnett Heads)
Jan 1985  to  Dec 2020  1.789
Gladstone Jan 1985  to  Dec 2020
2.401
Port Alma Jan 1986  to  Dec 2020  2.962
Rossyln Bay Jan 1993  to  Dec 2020 
2.488
Hay Point Jan 1985  to  Dec 2020 
3.434
Mackay Outer Harbour Jan 1985   to  Dec 2020 
3.076
Bugatti Reef Oct 1996  to  Mar 1997
1.607
Shute Harbour Jan 1987  to  Mar 2020
1.975
Bowen Jan 1986  to  Dec 2020
1.817
Abbot Point Jan 1985  to  Dec 1995
1.751
Cape Ferguson 
Jan 1991  to  Dec  2020  1.860
Townsville 
Jan 1985  to  Dec 2020  2.008
Lucinda (Offshore) Jun 1985  to  Dec 2020  1.951
Clump Point 
Dec 1985  to  Dec 2020  1.807
Mourilyan Harbour  Jan 1985  to  Dec 2020 1.803
Cairns Jan 1985  to  Dec 2020  1.746
Port Douglas  Jan 1987  to  Sep 2013 
1.654
Leggatt Island  Sep 1995  to  Apr 1996 
1.700
Twin Island Jul  1974  to  Dec 1975  1.810
Thursday Island Jan 1985  to  Dec 2020  1.919
Goods Island Nov 1989  to  Dec 2020  2.186
Booby Island Aug 1989  to  Dec 2020  2.480
Weipa (Humbug Point)  Jan 1985  to  Dec 2020  1.893 
Karumba Jan 1985  to  Dec 2020  2.167
Mornington Island  Jun 2007  to  Dec 2016 
2.164
Amrun (Boyd Point)  Jul 2018  to  Jan 2020 
1.892

Please refer to 2023 Tidal Planes for permanent marks and the Queensland Port Datum reference level. Australia height datum levels or details for determining Australia height datum levels for permanent marks can be sourced from Queensland Globe.

Last updated
23 January 2023