Boating in Australia: the best day to go

Two things run the day. The tide, which in Queensland is measured in metres and turns the depth in an anchorage into a moving number; and the bar, where a swell that was harmless offshore stands up over shallow water at the wrong state of the tide. Further south the southerly buster arrives after a hot day and turns a flat Sydney afternoon into a beat home.

Bonasea gives you tide height at your arrival and the depth in the anchorage corrected for it, and runs the ACCESS model over Australian waters rather than a global grid alone. What it will not do is tell you a bar is safe. That is a call for local knowledge, the current official warnings and your own eyes on the day, and no comfort score replaces any of the three.

Depth figures are modelled averages rather than a survey of your bay, and the comfort score is an estimate from weather models rather than a promise. Bonasea does not replace official charts, publications, regulations or the skipper’s judgement. Read the warnings for these waters before you leave, and trust your echo sounder over the app.