Follow this link to find the B.O.M.forecast for Port Phillip Bay.
You can find tide times and flows, too.
For tide times and flows:
look at the links at the bottom of the B.O.M. Port Phillip page. You will find a link titled "Marine And Ocean".
Follow this link and at the bottom left of the page you will see "Tides And Sea Level".
Follow this link, first select Victoria, second select Point Lonsdale in the locations list
(Williamstown gives an idea of the time of slack water, i.e. High/Low Water at Williamstown equals Slack Water at Port Phillip Heads).
Slack water lasts about 20 to 30 minutes before the tidal stream begins to flow.
Times shown are local time, i.e. you don't have to correct for daylight saving.
Remember that the tidal stream changes direction NOT at the time of high or low water, but about two and one half hours later, after slack water.