Meet the site
Lonsdale Bommies is a cluster of limestone outcrops on the outer Lonsdale reef, in Bass Strait about a kilometre off Point Lonsdale light and a couple of hundred metres east of Lonsdale Arches. The Scuba Doctor listing gives a depth of 12–18 m, an Open Water rating, an ebb-only tide window, and describes the same nutrient-rich, current-fed environment as the Arches: 'the strong current flow in this area has created a nutrient-rich environment and subsequently prolific marine growth and the associated marine life'. It is also noted, tellingly, as 'a favourite spot for catching crays' – the site lies within the marine national park where taking lobster is now prohibited, but the population that made the reputation is still there.
The bommies are rounded outcrops rising 3–5 m from a sand and rubble floor at 16–18 m, separated by gutters, with undercut bases and encrusted flanks. They lack the arches of the neighbouring site but have more edge, more crevices and, for a photographer, more places to find southern blue devils, cuttlefish, nudibranchs and the ubiquitous crayfish feelers. Above the reef the fish are those of the whole outer reef – sweep, boarfish, magpie perch, wrasse and leatherjackets – and seals drop in from the Point Lonsdale haul-outs.
Operators use the Bommies as the second dive of an 'outside' day after the Arches, or as the first drop when the Arches is crowded. The conditions that apply are the same: ebb slack, no significant south-westerly swell, and a boat that can pick divers up from a DSMB if they finish downstream. The site is easy and the navigation forgiving, and it is a good introduction to Bass Strait reef for divers who have only dived inside the bay. The Scuba Doctor listing also records an alternative Geoff Rodda mark (-38.282283, 144.646533) that is inside the Heads and appears to be an unrelated site.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Lonsdale Bommies is recorded as Pinnacle/Bommie in Port Phillip Heads. The listed access is boat. 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.
- Water movement
- Ask how swell and local exposure affect the proposed entry, exit and route.
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 Lonsdale Bommies 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 Lonsdale Bommies 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
Southern rock lobster, southern blue devil, giant Australian cuttlefish, nudibranchs, silver sweep, longsnout boarfish, magpie perch, bluethroat wrasse, leatherjackets, yellow zoanthids, sponges, Australian fur seal
Location
Rock outcrops on the outer Lonsdale reef in Bass Strait about 1 km from Point Lonsdale light, 200 m east of Lonsdale Arches and 142 m from Twin Bommies.
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.
