Meet the site
Half Moon Bay is the sheltered cove below the red sandstone bluff at Black Rock, best known for the hulk of HMVS Cerberus, the 1870 breastwork monitor scuttled as a breakwater in 1926, which sits 270 m offshore and is now so unstable that a protection zone bans entry. Divers still come to the bay for the small jetty and boat ramp in its southern corner. The jetty dive is shallow and easy: pylons in 2-4 m carrying mussels, sea squirts and sponges, with small leatherjackets, gobbleguts (southern cardinalfish), sea stars, anemones, urchins and nudibranchs, the occasional seahorse and, in the holes and under debris, southern blue-ringed octopus, which should be admired and left alone. West of the jetty the bottom is open sand and seagrass at 5-6 m, dull by day but transformed at night, when octopus, flathead, bull rays and stingarees move over it and the plankton lights up with every fin stroke. Spring night dives here are a Melbourne club tradition for that reason. The site's other attraction is shelter: tucked under the bluff and facing west, it is diveable in most winds except southerlies, and the small size of the bay makes navigation trivial. It suits new divers, night-dive courses, snorkellers and anyone with an hour to spare on the bayside. Parking is the practical limit; the car park at the bottom of the hill is small and metered and can be full by mid-morning on a fine weekend. Ricketts Point Marine Sanctuary begins a kilometre to the south-east and its Quiet Corner entry is the next site along.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Black Rock Jetty, Half Moon Bay is recorded as Jetty/Pier 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.
- Lines and obstructions
- Discuss any known entanglement concerns and the suitability of the planned area.
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 Black Rock Jetty, Half Moon Bay suitable for my certification?
The record lists Open Water. 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 Black Rock Jetty, Half Moon Bay 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, southern cardinalfish (gobbleguts), seahorses, sea stars, anemones, sea urchins, nudibranchs, southern blue-ringed octopus, octopus, flathead, bull rays and stingarees at night
Location
Short jetty and boat ramp in Half Moon Bay, Black Rock, below the Red Bluff cliffs; the protected wreck of HMVS Cerberus lies 270 m offshore (a separate site with a no-entry zone).
Facilities nearby
Small metered car park; public toilets; life saving club and yacht club; Cerberus Beach House cafe; nearest air fills Scuba Culture (Cheltenham)
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.auscubadoctor.com.auRecord updated 26 Sept 2026. Source claims are being reviewed.
