Meet the site
The Jawbone is a lobe of the Newer Volcanics lava that reached Port Phillip at Williamstown, and its shoreline is a chaos of basalt boulders, ledges, seagrass and saltmarsh that has been protected since 2002 as the Jawbone Marine Sanctuary, backed on land by the Jawbone Flora and Fauna Reserve. It is not an easy access: the walk from the Esplanade parking is 250 m or more via the Bay Trail, the entry is over slippery rock and shingle, and there are no facilities. The reward is one of the more distinctive habitats in the bay. The bottom is basalt boulders thickly encrusted with tubeworms and mussels, with sea stars, crabs, shrimps and common sea urchins in every gap, abalone on the rock, nudibranchs on the sponges and a good fish community of zebrafish, dusky morwong, leatherjackets, wrasse and blennies. Seasonally there are dumpling squid, seahorses in the seagrass, octopus in the boulders and small sharks (Port Jacksons and draughtboard sharks) resting under ledges. Depth is 2-6 m and the reef grades outward into seagrass and sand. Because it is a no-take zone the abalone and crayfish that were stripped from the rest of the western shore are slowly returning, which makes it a useful comparison with the unprotected reef outside. It is calmer than Williamstown Beach breakwater in a southerly because East Point breaks the fetch, and it is a good, if effortful, night dive. Dive it at high tide; at low water it is snorkelling depth at best. The Jawbone West entry and the sanctuary overview are documented separately.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
The Jawbone, Williamstown is recorded as Shore/Rock Platform 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 The Jawbone, Williamstown 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 The Jawbone, Williamstown 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
Zebrafish, dusky morwong, leatherjackets, wrasse, blennies, abalone, common sea urchins, sea stars, crabs, shrimps, nudibranchs, dumpling squid, seahorses, octopus, Port Jackson and draughtboard sharks (seasonal)
Location
Basalt boulder reef entered just north of East Point at the eastern edge of the Jawbone Marine Sanctuary, below Gloucester Reserve and the Esplanade, Williamstown.
Facilities nearby
Roadside parking on the Esplanade only; no toilets or change rooms; nearest facilities at Williamstown Beach 700 m east; nearest air fills Dive Victoria Group
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.auparks.vic.gov.auRecord updated 26 Sept 2026. Source claims are being reviewed.
