Meet the site
Named tongue-in-cheek after the southern ocean embayment, this site is a field of coral bommies on Thevenard's southern side at 5–8 m, with tuskfish, angelfish and numerous nudibranchs, per the Marine Life Network.
About the Mackerel Islands: the group of ten low islands off Onslow, including Thevenard and Direction islands, sits just north of the Ningaloo Coast and Exmouth Gulf. The Marine Life Network documents a dozen dive sites within easy reach of Thevenard, from shallow coral heads to ledges, caves and canyons at up to 20 m, and the resort notes whales, dolphins, groper, reef sharks, stingrays, wobbegongs, turtles and thick schools of trevally, snapper, fusiliers and batfish. With no resident operator and few visiting divers, the reefs are among the least dived in the region — ideal for self-sufficient divers with their own boat.
Planning notes: Open Water certification is recommended and the site is rated beginner. Expect to spend most of the dive around 6 m, with a maximum of about 8 m. Access is by boat only, and site selection depends on wind, swell and tide on the day. Best season: April–October. Traffic: rarely dived (private boat/club only).
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Great Australian Bight (Thevenard) is recorded as Pinnacle/Bommie in Pilbara & Dampier. 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.
- Current and timing
- Ask how the operator assesses the current window for the actual route. Historical tide notes are not a departure instruction.
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 Great Australian Bight (Thevenard) 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 Great Australian Bight (Thevenard) 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
Tuskfish, angelfish, nudibranchs, reef fish
Location
Coral bommies on the southern side of Thevenard Island, 5–8 m, jokingly named the Great Australian Bight.
Facilities nearby
Mackerel Islands resort on Thevenard Island: accommodation, snorkel gear hire, boat hire. No air fills – bring filled cylinders or arrange via Karratha.
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.aumackerelislands.com.auRecord updated 26 Sept 2026. Source claims are being reviewed.