The Port Phillip Bay Side of the Mornington Peninsula offers a remarkably varied diving scene, from shallow pier dives at Blairgowrie and Rye through to deep walls and wrecks off Portsea. Kelp forest, seagrass, artificial reefs and dramatic wall systems all feature. The signature species list is truly distinctive: Weedy Seadragon, Pot-bellied Seahorse, Giant Cuttlefish and Fiddler Ray are consistently observed across the sites. Portsea and Sorrento hold the largest concentration of sites, with calmer, shallower options around Blairgowrie and Rye suiting beginners and snorkellers.
Monthly water temperature across Port Phillip Bay Side's sites, from satellite sea-surface data corrected for depth. The band shows the site-to-site spread.
Water is warmest over the summer months, from December through March, which also aligns with the peak in diver activity. Temperatures drop noticeably through autumn and reach their coolest in the middle of winter. Conditions at sheltered pier and reef sites remain diveable year-round, but the exposed wall and drift sites off Portsea are strongly influenced by tidal currents and suit confident, well-planned dives.
32 operators
43 more sites to explore
4 areas
20Tidal reef, wall, and wreck diving on Victoria's Mornington Peninsula, with Weedy Seadragon, Port Jackson Shark, and deep submarine wrecks.
16Port Phillip Bay diving with Weedy Seadragon, Giant Cuttlefish and drift dives through the Heads. Strong marine life across reef, kelp forest and artificial reef sites.
5Mornington Peninsula pier and reef diving in cool Port Phillip Bay waters, known for seahorses, nudibranchs, fiddler rays, and fur seals.
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Water temperature around Port Phillip Bay Side ranges from about 13°C in July to 19°C in January, based on satellite sea-temperature data for its dive sites.
In the warm season (about 19°C) a 5mm suit is comfortable in Port Phillip Bay Side; in the coldest months (about 13°C) step up to a 7mm or semi-dry suit.
Fin maps 55 sites in Port Phillip Bay Side (53 scuba diving sites and 14 snorkelling spots, with some suited to both), organised into 4 areas.
Across Port Phillip Bay Side's dive sites, January, February, March, April, May and December are most often reported as the best months to visit.
The region has a well-documented list of observed species. Fiddler Ray, Smooth Ray and Magpie Morwong are among the most frequently encountered. Weedy Seadragon and Pot-bellied Seahorse are regularly sighted at pier and reef sites, and Giant Cuttlefish are common across much of the area. Blue-ringed Octopus, Port Jackson Shark and a wide variety of nudibranchs including Chromodoris Nudibranch and Short-tailed Ceratosoma round out the highlights.
Yes, a good portion of the sites are rated beginner level. Blairgowrie Pier, Rye Pier and Cottage by the Sea all offer shallow shore dives with easy entries. Popes Eye is a beginner-friendly boat dive as well. The more advanced sites, such as Lonsdale Wall and the Rotomahana Wreck, are best left to experienced divers comfortable with depth and current.
Portsea has the greatest number of sites and includes the region's most demanding dives, among them deep walls, drift sites and the HMAS J5 Submarine wreck. Sorrento offers a solid mid-range mix of reef and wall dives. Blairgowrie is centred on its well-known pier site and the challenging kelp-forest dive at Diamond Bay. Rye is the smallest sub-area, with shallow, accessible sites well suited to beginners and snorkellers.
Shore access is available at a number of popular sites, including Blairgowrie Pier, Rye Pier and Cottage by the Sea, making them convenient for divers and snorkellers without a boat. However, several of the more exposed and deeper sites, including Lonsdale Wall, Boarfish Reef and the wreck sites off Portsea, require boat access. Operators such as Ocean Divers, Diving Victoria and Snorkel and Dive Safari run boat charters throughout the region.
