Meet the site
Lihou Reef is the largest atoll in the Coral Sea, a U-shaped reef enclosing a lagoon roughly 100 km long and 30 km wide, with about 18 small islets on its rim. Marinelife.org.au notes that it was a nature reserve, that marine seaweed beds are prevalent, and that commercial tours were limited to 10 a year. It is now part of the Coral Sea Marine Park, zoned partly National Park Zone and partly Habitat Protection Zone, and part of the Coringa-Herald and Lihou Reefs and Cays Ramsar Site. The Parks Australia zoning map names features including Hermit Crab Islet, East, Central and West Diamond islets, Turtle Islet and South West Cay.
The atoll has a long history of shipwrecks.
The reef itself is almost untouched by divers. Expect shallow lagoon bommies, extensive reef flats and seagrass or seaweed beds inside, and outer walls dropping into deep water outside, with reef sharks, groupers, trevally, turtles and seabirds. Visibility on the outer walls is usually 30 m or more, while the lagoon can be less clear.
Lihou is for self-sufficient expedition divers on a capable vessel with an experienced skipper. Narrow passages into the lagoon are hazardous. The rewards are isolation and a reef system seen by very few people.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Lihou Reef is recorded as Reef in Coral Sea. The listed access is boat (multi-day/liveaboard). 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 Lihou Reef suitable for my certification?
The record lists Deep/Advanced + experience. 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 Lihou Reef 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
Reef sharks, groupers, trevally, turtles, reef fish, seaweed and seagrass beds; seabird colonies on the islets
Location
The largest atoll in the Coral Sea, a U-shaped reef enclosing a 100 by 30 km lagoon with about 18 small islets, some 550 km east of Townsville.
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.auaustralianmarineparks.gov.auoceans1.customer.netspace.net.auaustralianmarineparks.gov.auRecord updated 27 Sept 2026. Source claims are being reviewed.
