Scuba diving in Victoria

Everything inside the bay is governed by the tide at the Rip. Slack water at the Heads occurs roughly three hours after high or low water at Port Phillip Heads, but the offset varies with wind and barometric pressure, and dive operators use their own tables. Charters out of Queenscliff, Portsea and Sorrento run the Heads walls, the ships' graveyard wrecks and the Canberra on the appropriate slack, often with two dives on the same tide cycle. Inside the bay the piers and shore reefs from Rye to Portsea are almost tide-independent but are exposed to northerly winds; the bayside suburbs (Black Rock, Beaumaris, Ricketts Point) are shallow, silty and best on southerlies. Bass Strait and the back beaches of the Peninsula need swell under 1.5 m and are typically only diveable a handful of days a month.

Late summer and autumn (February to May) bring the warmest water (17–20 °C), the most settled weather and the clearest water at the Heads. Winter is cold (11–13 °C) but frequently flat, and the giant spider crab aggregation in May and June and the giant cuttlefish season in late winter are worth the discomfort. Wilsons Promontory and the Shipwreck Coast are summer and autumn destinations, dived in windows of northerly or light winds when the swell drops.

Victoria has a strong club culture and shore diving is completely independent: fill up, check the tide, and go. Shops in Portsea, Rye, Mornington, Queenscliff, Melbourne's bayside and Geelong hire drysuits and run charters. Heads dives are boat-only and most operators want Advanced Open Water and a log of recent cold-water dives; the deeper graveyard wrecks and the J4 and J5 submarines suit technical or very experienced recreational divers.