Meet the site
Cerberus is the most important warship wreck in Victoria and the one nobody is allowed to dive. She was the world's first breastwork monitor – a low, heavily armoured, twin-turreted iron warship designed by Edward Reed and built by Palmers at Jarrow-on-Tyne, launched on 2 December 1868 and completed in 1870 for the colony of Victoria's own navy. Sixty-eight metres (225 ft) long with four 10-inch muzzle-loading guns in two turrets, she was the first ship to combine a central superstructure with turrets fore and aft, the pattern of every battleship for the next 80 years, and the first British warship to dispense with sail entirely. She steamed out to Melbourne in 1871 and guarded Port Phillip for the Victorian Navy, the Commonwealth Naval Forces and the Royal Australian Navy until 1924 without ever firing a shot in anger. Sold for scrap, her hull was bought by Sandringham Council and on 2 September 1926 scuttled off Half Moon Bay as a breakwater for the Black Rock Yacht Club. For decades she was a dive and snorkel site with the turrets and breastwork standing above water. Corrosion caught up with her: by the 1990s the hull was sagging, in 1993 the deck collapsed, and the wreck has now collapsed to the waterline, crushing the passageways in the lower hull. The four guns were lifted off in 2005 and placed on the seabed beside the hull, where they undergo in-situ conservation with sacrificial anodes. A 0.5-hectare protection zone surrounds the site and diving or snorkelling within it is prohibited without a Heritage Victoria permit. What the visitor gets is a view: the rusting breastwork and turret bases 200 m off a popular beach, best appreciated from the cliff path or a kayak, with the story told on interpretive signs and by the Friends of the Cerberus. The reef along the Half Moon Bay cliffs outside the zone is a pleasant shallow snorkel with leatherjackets, sea stars, sponges and the occasional seahorse. Cerberus is included here for completeness and because divers regularly ask about it; the answer is that the world's only surviving monitor of her type is a heritage site, not a dive.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
HMVS Cerberus is recorded as Wreck in Melbourne & Port Phillip Bay. The listed access is shore. Confirm the actual meeting point, route and permission to visit; a map pin does not establish any of these.
Topics flagged by the stored research
These are questions prompted by the existing notes, not a verified or complete hazard assessment.
- Other water users
- Ask about vessel activity, exclusion areas and the agreed surface arrangements.
Historical access notes exist for this record, but have not been independently verified for current use. Request current directions from the operator or site manager rather than following an old entry description.
Questions, answered
Is HMVS Cerberus suitable for my certification?
The record lists Snorkel/Any. That does not establish suitability for every route or day. Share your training, recent experience and equipment needs with the operator and ask about the specific proposed dive.
Can I book HMVS Cerberus through YouDive?
YouDive is an independent research directory. Contact an operator directly to confirm whether it currently runs the trip, the inclusions and the booking terms.
What you might see
Leatherjackets, sea stars, sponges, seahorses and pipefish on the surrounding reef; mussels and weed on the hull
Location
Scuttled as a breakwater about 200 m off the beach at Half Moon Bay, Black Rock, in Melbourne's bayside suburbs; the collapsed hull stands above water inside a 0.5 ha protection zone.
Facilities nearby
Paid foreshore car park, toilets, life saving club, cafe, yacht club at Half Moon Bay; fills at bayside dive shops.
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.aucerberus.com.auRecord updated 27 Sept 2026. Source claims are being reviewed.
