Meet the site
Popes Eye is an artificial island that was never finished. In the 1880s the colony of Victoria began a ring fort on a shoal 4 km inside the Heads as part of the defence of Port Phillip; a horseshoe of bluestone blocks was laid – the Scuba Doctor listing gives its dimensions as about 204 m long, 22.4 m wide at the base tapering to 1.3 m at the top and rising 2.8 m above low water – before advances in gunnery made it redundant and work stopped. Left alone, it became a reef, and since 1979 it has been a marine reserve; it is now part of Port Phillip Heads Marine National Park and the oldest protected piece of seabed in Victoria.
The horseshoe faces roughly north-east, and the dive has two parts. Inside the annulus the water is 1.5–4 m deep, calm and full of fish that have never been hunted: old wives, scalyfin, zebrafish, sweep, leatherjackets, magpie perch and big bluethroat wrasse crowd around divers and snorkellers. Outside, the bluestone drops to sand at about 10 m (14 m at the deepest) and the blocks are covered in gorgonian fans, feather stars, sponges and kelp, with sea urchins, abalone and nudibranchs among them. A ship's anchor lies at 12 m on the ebb side and an old wooden butter churn on the flood side, both useful for navigation. Giant cuttlefish are regular in winter, and Australian fur seals from Chinamans Hat 2.5 km to the east visit constantly; above the water a colony of Australasian gannets nests on the platform, the only mainland-attached gannet colony in Australia.
Popes Eye is the beginner's Heads dive and the peninsula's snorkel site, but experienced divers should not skip it: the fish density and approachability are unlike anywhere else in the bay, and the structure is a reliable night dive. It is dived on almost any tide, though the current outside the walls is strong on springs and the start of the ebb is best.
What you might see
Australian fur seal, Australasian gannet (nesting), giant cuttlefish, old wife, scalyfin, zebrafish, silver sweep, leatherjackets, magpie perch, bluethroat wrasse, gorgonian fans, feather stars, sponges, sea urchins, abalone, nudibranchs, octopus
Location
An unfinished horseshoe-shaped bluestone fort foundation about 4 km inside The Heads, midway between Queenscliff and Portsea on the edge of the West Channel; the Anchor Farm lies 88 m to the north.
Before you make plans
Conditions, access and operator schedules can change. This is a location guide, not a dive plan. Ask a local operator about current conditions and suitability for your training and experience.
Sources & further reading
scubadoctor.com.auscubadoctor.com.auen.wikipedia.orgparks.vic.gov.auRecord updated 26 Sept 2026. Source claims are being reviewed.
