Meet the site
Castle Rock is the granite landmark that gives Castle Bay its name, and the rocky outcrops around it are among the best snorkelling spots in Meelup Regional Park. Meelup Park describes Castle Bay's spectacular backdrop of Castle Rock with rocky outcrops that host an array of marine life, suitable for snorkelling and diving, and notes that winter surfing takes place there in strong swells. The Margaret River region's safety guide names Eagle Bay, Castle Rock and Rocky Point for their beautiful rock formations, suitable for snorkelling and freediving, and a south-west snorkel guide calls Castle Rock more rugged and secluded than Eagle Bay.
The granite boulders form gutters, overhangs and small swim-throughs in shallow water, with weed, sponges and invertebrates on the rock and seagrass between. Fish life includes wrasse, western blue devils, buffalo bream and old wives, and octopus and crabs are common in the cracks.
It suits snorkellers and shore divers of all levels in calm weather, and is a step up in interest from the sandy beaches. Depths are modest, so scuba divers get long, relaxed dives. As with other Meelup sites, avoid it when a big winter swell is running into the bay.
Geographe Bay faces north, so Cape Naturaliste blocks most of the prevailing south-westerly swell and sea breeze that close the ocean coast; that shelter and the warm Leeuwin Current make the Dunsborough shoreline one of the most reliably diveable stretches of the South West, and winter north-westerly storms are the main thing that shuts it down.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Castle Rock (Castle Bay) is recorded as Shore/Rock Platform in Geographe Bay & Busselton. 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.
- 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 Castle Rock (Castle Bay) 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 Castle Rock (Castle Bay) 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
Western king wrasse, western blue devil, buffalo bream, old wife, octopus, crabs, sponges, seagrass fauna
Location
Granite outcrops and reef around Castle Rock at Castle Bay in Meelup Regional Park, between Dunsborough and Eagle Bay, used for snorkelling, diving and winter surfing.
Facilities nearby
Car park; limited facilities - toilets at Meelup Beach; Dunsborough 5-6 km.
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
meeluppark.commargaretriver.comprivateproperties.com.auen.wikipedia.orgRecord updated 27 Sept 2026. Source claims are being reviewed.