The Port Phillip Bay snapper rule (and why wind matters more than tide)
Port Phillip Bay is the most productive recreational fishery in Australia, and 90% of the time the difference between a hero day and a wasted Sunday is the wind. The bay is shallow (mostly under 25 m) and an open mouth at the Heads — so a 25 kt southerly turns it into a chocolate milkshake within 6 hours. BayCast wraps every PPB launch in one page so you can decide on Friday night whether Saturday's worth the diesel.
For most spots: under 15 kt is GO, 15–22 kt is CAUTION (bay-specific — pick the lee shore), over 22 kt is NO-GO unless you're under the Mornington wall.
Best times for snapper in Port Phillip Bay
Snapper run mid-September to late January, with the peak the first 6 weeks after the Cup. The best three windows in any week are:
- Pre-dawn 04:30–07:30 on a tide change — works at Mt Martha, Frankston, Mordialloc, Werribee, Geelong
- Last 90 minutes before sunset on a building tide — works at every east-shore launch
- Full moon nights with a slow run-in tide — old-school St Kilda, Brighton and Hobsons Bay snapper
Tide rule of thumb: most PPB snapper anglers prefer the run-in. Bottom of the low to top of the high. The bait moves with the water, the snapper move with the bait.
Where to launch for which species
Snapper: Mt Martha, Frankston, Mordialloc, Werribee, Corio Bay. King George whiting: Sorrento, Rye, Queenscliff, Blairgowrie. Calamari: Rye Pier, Blairgowrie, Queenscliff weed beds, Mt Martha. Flathead: sand patches everywhere — drift the channels at Rye and Sorrento. Australian salmon: Sorrento back, St Leonards, Geelong waterfront from May.
Wind direction cheat sheet for PPB
- Light NW or N: bay flat — every launch is on. Best day of the week.
- NE under 12 kt: east shore good (Frankston, Mt Martha). West shore lumpy.
- SW 15+ kt: stay east. Mt Martha and Frankston are sheltered.
- S/SSE over 18 kt: the bay turns over. Don't bother unless Geelong.
- E 15+ kt: Geelong, Werribee. Avoid east shore.
Tides at the Heads vs interior bay
Port Phillip's tide range at the Heads is around 1 m but inside the bay it drops to 0.4–0.8 m by the time it reaches Geelong. The lag is real — high tide at the Heads is 1.5 hours before high tide at Werribee. BayCast pulls the local sea-level forecast for each launch so you don't have to do tide math.
What we're not
BayCast is a planning tool. We use Open-Meteo Marine forecasts and your phone's clock. Tide predictions are predictions — the actual water level on the day depends on barometric pressure, wind set-up and ocean swell. Always cross-check the BoM marine forecast before you launch.