Meet the site
The Sisters are a group of limestone reefs at the southern end of Shoalwater Islands Marine Park in Warnbro Sound, marked by rocks breaking the surface. The City of Rockingham lists them as a scuba and snorkelling site in 2–6 m, and the Marine Life Network describes a beginner-friendly dive of about 8 m with ledges and caves.
The reef is typical Warnbro Sound limestone: flat tops covered in kelp and red algae, with ledges, small overhangs and caves around the edges and sand between. Many wrasse species, buffalo bream, sweep, herring cale and leatherjackets move over the reef, and rays rest on the sand. Nudibranchs and sponges grow under the ledges. Resident Australian sea lions from the Shoalwater islands often visit divers here, which is one of the site's attractions.
The historic wreck of the Chalmers, a timber barque lost in 1874, lies in 3 m on the Sisters reef system. Little remains beyond a kelp-covered ballast mound and scattered fittings, but it can be visited on the same trip.
With shallow depths, short boat rides and plenty of structure, the Sisters suit newly certified divers and snorkellers from private boats. They are exposed to south-westerly swell, so choose a calm day. As within the rest of the marine park, check sanctuary zone boundaries before fishing, and give sea lions space.
The Sisters make a good combination with the Saxon Ranger or First Rock for a two-dive morning out of Safety Bay, keeping boat runs short and depths moderate. Published information is limited to two sources, so check depths and anchoring spots on the sounder before descending.
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 Sisters (Warnbro Sound) is recorded as Reef in Perth. 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 The Sisters (Warnbro Sound) 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 Sisters (Warnbro Sound) 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
Wrasse (many species), buffalo bream, sweep, herring cale, leatherjackets, rays, nudibranchs, sponges, Australian sea lions
Location
Limestone reefs marked by protruding rocks at the southern end of Shoalwater Islands Marine Park in Warnbro Sound.
Facilities nearby
Bent Street, Carlisle Street, Donald Drive and Port Kennedy boat ramps: parking, toilets at most.
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
marinelife.org.aurockingham.wa.gov.auRecord updated 26 Sept 2026. Source claims are being reviewed.
