Tides and Fishing in Australia

Why the tide comes first on the coast

On an Australian estuary, bay or beach the tide decides more than the weather does. Bream feed on the run, flathead lie where the falling tide drains the flats, whiting work the sand on the rise, mulloway hold in the channels at the change, and on the tropical coast the whole fishery, barramundi on the run-off and the creek mouths, moves with metres of water. The coastal water pages on this site put the tide panel next to the report for that reason, and the fishing-times module uses the modelled tide changes as one of its inputs.

Hervey Bay → · Mandurah →

What the panel shows, and what it is

The panel shows the next highs and lows and an hourly curve for the day. The curve is sea level height above mean sea level from Open-Meteo’s marine model, computed for the coordinates of the water. It is a model, not the Bureau of Meteorology’s tide prediction: the Bureau’s predictions are Commonwealth copyright, published under the Bureau’s own conditions of use for tide information, with the full set sold as a registered data service. This site does not copy them, and the panel is labelled “modelled” so nobody mistakes one for the other. The Bureau’s official table is linked from every coastal page for the exact minute.

How far the model can drift

On an open coast the model and the official table usually agree on the direction of the tide and the rough time of the change. Inside a long bay, an estuary behind a bar, or a river with a tidal reach, the model can drift by tens of minutes and more, because it does not know the bar, the channel or the entrance that delays the water. Port Phillip is the Bureau’s own example of a partially enclosed bay with a small range, where Melbourne’s tide typically changes by less than a metre and runs to its own timetable inside the Heads; in a coastal lake with a shoaling entrance the tide may barely reach the lake at all. Use the curve for direction and size, and take the minute from the Bureau where the minute matters.

Port Phillip → · Lake Macquarie →

Australia has more than one kind of tide

The Bureau puts the average spring range at under a metre in the south-west and at more than eight metres in the north-west, where the wide, shallow North West Shelf builds big tides at Broome and, of the major ports, the largest range of all at Derby, which can change by more than 11.5 metres in as little as six hours. The flats and creeks there are a different fishery on every hour. The Gulf of Carpentaria is a different case again: the middle of the Gulf sits near a point of almost no tidal range, and the Bureau singles it out for slow seasonal swings in sea level, so the model is least reliable there and the official table most needed. The tide is amplified as it runs up the South Australian gulfs, where the neap days of barely moving water are known locally as the dodge tide, and it is amplified again from either side of Bass Strait, which makes the channels of the Strait and the north coast of Tasmania run hard. The editorial guide of each coastal water says which of these it has.

Broome → · Karumba → · Port River, Adelaide →

Springs, neaps and the moon

Around the full and new moon the tides are larger, the springs; around the quarters they are smaller, the neaps. Big springs move more water, which stirs the flats, colours the estuaries and concentrates fish on the edges of the run; neaps give clearer water and slower drifts that suit whiting on the flats and squid over the weed. The moon module on every page shows the phase, and the tide panel shows the range for the day, so you can see whether you are on a spring or a neap without a table.

Reading the tide with the weather

A falling barometer ahead of a front on a rising tide at dusk is the best combination the coastal pages can show, and the fishing-times module will put its brightest bars there. A strong onshore wind on a big spring tide colours the water and pushes the fishing into the lee and the estuaries. On the beaches the falling tide exposes the gutters and the rising tide fills them, and the gutters fish on the rise at dawn and dusk. The tide is one input of the bite forecast, alongside sunrise, sunset, the moon and the day’s score; it is not the whole of it, and on a lake it is not there at all.

What would change this page

If the Bureau of Meteorology grants a data licence for its tide predictions, the coastal pages will show the official times and say so, and the change will be recorded in the verification log. Until then the model stays, labelled, and the official table stays linked. That is the site’s rule for every number: read from a source that can be named, or labelled as a model, never presented as more than it is.

The verification log → · How our reports are made →

Common questions