Meet the site
Marmion Marine Park, declared in 1987 as Western Australia's first marine park, stretches about 20 km from Trigg Island to Burns Beach and protects more than 136 fish species, ten seagrass species and 21 seabird species. DBCA's guide lists The Lumps among the inshore reefs, with Boyinaboat Reef, Cow Rocks, Wanneroo Reef, Wreck Rock, Whitfords Rock and Burns Rock, that attract divers with intricate overhangs, ledges, caves and swim-throughs. SSI's Perth guide names North Lump as one of the park's dive features, with blue groper, crayfish, Port Jackson sharks and corals.
The Lumps are limestone bommies and reef patches rising from sand and seagrass. Their tops are covered in kelp and algae, and their sides are undercut into ledges and small caves that shelter western rock lobster, Port Jackson sharks (especially in winter and spring), wobbegongs and buffalo bream. Wrasse, scalyfin, western blue devils, old wives, morwong and bullseyes are common, along with sponges and small corals.
The inshore position makes the reefs a short boat ride from Hillarys and gives them some protection from the swell, but visibility is usually lower than at Three Mile Reef and Little Island.
The site suits Open Water divers and is a good choice for an easy boat dive or a second dive. Depths and positions have not been published in detail, so this record relies on the park guide and general descriptions of Marmion's inshore reefs; ask the operator or check the sounder.
As with all of Marmion's reefs, check sanctuary zone boundaries before fishing, and do not take lobsters from sanctuary areas.
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 Lumps (Marmion) 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.
- Lines and obstructions
- Discuss any known entanglement concerns and the suitability of the planned area.
- 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 Lumps (Marmion) 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 Lumps (Marmion) 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
Blue groper, western rock lobster, Port Jackson sharks, wobbegongs, buffalo bream, wrasse, scalyfin, western blue devils, old wives, morwong, bullseyes, sponges, corals
Location
Inshore limestone reefs and bommies in Marmion Marine Park off Hillarys and Sorrento, with overhangs, ledges, caves and swim-throughs.
Facilities nearby
Hillarys Boat Harbour ramps, parking, toilets, dive shops and air fills.
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
trailswa.com.audivessi.comimagedive.com.auRecord updated 26 Sept 2026. Source claims are being reviewed.
