Spot-level summary for depth and typical wildlife at Four Mile Reef.
Four Mile Reef
Short-boat Busselton reef with sharks, rays, and temperate coral.
About Four Mile Reef
Four Mile Reef is a short-boat temperate reef dive off Busselton where low limestone reef, sponge and soft-coral growth, and sandy gaps create an easy-to-read site for recreational divers. The reef is known for varied South West marine life rather than dramatic relief. Divers typically cruise across broken reef looking for schooling fish, rays, cuttlefish, wobbegongs, and Port Jackson sharks while enjoying a straightforward profile in moderate depth.
Research Estimate At Four Mile Reef
Conservative baseline from public research. No community dives logged yet.
Where Is Four Mile Reef?
Four Mile Reef Planning Details
Depth range, seasonality, and planning context.
Reported Depth
18m - 22m
Depth Note
Described as an 18 m reef dive.
Best Season
Autumn through spring often brings the clearest and most comfortable diving windows, while calmer summer periods can still work well when wind stays down.
Typical Conditions
Expect temperate reef growth, sandy sections, and workable visibility that can change quickly with swell, wind, and runoff across Geographe Bay.
Safety & Access At Four Mile Reef
Hazards, restrictions, and access requirements.
Key Hazards
Safety Notes
This is a boat-access offshore reef, so divers should plan for surface conditions, blue-water ascent discipline near the boat, and occasional surge if Geographe Bay is unsettled.
Access Restrictions
Access is typically by charter or private boat from Busselton area ramps or marinas; conditions in Geographe Bay determine whether the site is worth running on the day.
Legal Notes
Standard Western Australian marine-life protections apply. Divers should avoid disturbing protected species and follow local boating and fishing rules for the Busselton and Geographe Bay coast.
Local Intel For Four Mile Reef
Community notes to help plan your visit.
Scuba
A reef dive around 18 m depth.
Freedive
Possible for experienced boat-based freedivers, but Four Mile Reef is used far more often as a scuba site than as a dedicated breath-hold destination.
Snorkel
Not a typical snorkel stop because access is by boat and the reef sits offshore in open bay water rather than a protected shoreline lagoon.
Four Mile Reef Dive Conditions Planner
Use the planner to scan this week, inspect today in local time, and understand how exposure shapes conditions at Four Mile Reef.
Exposure Profile at Four Mile Reef
Directional shelter context for incoming swell.
Wildlife at Four Mile Reef
Species commonly reported at this site, with direct links into their wildlife guides.
Recent Logged Visits At Four Mile Reef
Community dive logs and visit reports for this site.
No Dive Logs Yet
Be the first to log a dive at this spot and share your experience!
Dive Spot Log Averages At Four Mile Reef
Average conditions based on logged dives & visits.
Four Mile Reef Guide - Frequently Asked Questions
Planning answers for access, conditions, timing, and site logistics.
Four Mile Reef Guide - Sources and Updates
Last Updated
Research Sources
Regional South West diving overview and visibility/conditions context.
Regional Busselton dive operator context for local boat diving and temperate marine life.
Know this site? Improve Spot Details.



