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. Little Island is a small, flat sand and limestone island off Hillarys, inside a sanctuary zone. It is one of three places near Perth where the public regularly sees Australian sea lions hauled out, and DBCA's guide describes it, with Three Mile Reef, as an offshore reef with better visibility than the inshore sites.
The Marine Life Network describes a shallow, protected site of 5–10 m around the island, good for snorkelling, with seals and seabirds. The reef has ledges and low overhangs covered in algae, and supports buffalo bream, wrasse, sweep, herring cale, western blue devils and schools of baitfish, with crayfish, stingrays and cuttlefish. Bottlenose dolphins are common, humpback whales pass in spring, and turtles are occasionally seen.
Most sea lions near Perth are males that move between here, Burns Rock, Carnac and the Shoalwater islands and breed at colonies off Jurien Bay every 17–18 months. In the water they are curious and may come close. Keep at least 10 m away, never approach animals on the beach and do not feed or touch them.
Little Island suits snorkellers and divers of all levels on calm days, and it is one of the easiest wildlife encounters in Perth. Beaching kayaks is prohibited. Humpback whales pass the island from September to November, when whale-watching boats also work the area.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Little Island (Marmion) is recorded as Island 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 Little Island (Marmion) suitable for my certification?
The record lists Snorkel/Any. 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 Little Island (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
Australian sea lions, bottlenose dolphins, humpback whales (spring), occasional turtles, buffalo bream, wrasse, sweep, herring cale, western blue devils, baitfish, western rock lobster, stingrays, cuttlefish, seabirds
Location
Small, flat limestone and sand island off Hillarys in a Marmion Marine Park sanctuary zone, an Australian sea lion haul-out with shallow protected reef around it.
Facilities nearby
Hillarys Boat Harbour ramps, parking, toilets and dive shops.
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
en.wikipedia.orgtrailswa.com.aumarinelife.org.audivessi.comRecord updated 27 Sept 2026. Source claims are being reviewed.
