These are the sites few divers ever reach: Coral Sea seamounts, the Rowley Shoals, the far northern Great Barrier Reef, the Kimberley coast, Bass Strait islands and the offshore territories. Most are liveaboard or expedition access only, and the nearest recompression chamber is often a day away.
Ranked by distance offshore among sites recorded as remote or expedition-only, then by how rarely they are dived.
Updated daily from the directory. 30 sites listed.
1. Swain Reefs · QLD
Offshore: 220 km · A circular reef and drop-off at the northern limit of southern charters, with sharks, grouper and sea snakes.
2. Swain Reefs · QLD
Offshore: 220 km · Shallow coral gardens suited to macro photography.
3. Swain Reefs · QLD
Offshore: 220 km · A maze of bommies, gutters and staghorn thickets with sea snakes and big fish.

4. Swain Reefs · QLD
Offshore: 220 km · Fish-packed coral pinnacles to 35 m beneath a protected seabird rookery, with sharks and mantas.
5. Swain Reefs · QLD
Offshore: 220 km · A sheltered anchorage with bright shallow coral gardens and sharks and pelagics deeper.
6. Swain Reefs · QLD
Offshore: 220 km · Coral garden complex with excellent fish and invertebrate life, recovering well.
7. Swain Reefs · QLD
Offshore: 220 km · The Swains' most varied reef: a big sheltered lagoon, deep walls to 35 m and a wreck site.
8. Swain Reefs · QLD
Offshore: 220 km · Ledges and gutters home to giant grouper up to 2 m.
9. Swain Reefs · QLD
Offshore: 220 km · A deep drop-off hung with huge yellow and red gorgonian fans.
10. Swain Reefs · QLD
Offshore: 220 km · Coral pinnacles where mantas come to cleaning stations in winter.
11. Swain Reefs · QLD
Offshore: 220 km · Invertebrate-rich coral gardens full of flatworms, nudibranchs and sea stars.
12. Swain Reefs · QLD
Offshore: 220 km · A maze of deep gutters through coral gardens, with batfish, grouper and sea snakes.
13. Swain Reefs · QLD
Offshore: 220 km · Deep, colourful Swains walls to 40 m with pelagic schools – for experienced divers only.
14. Swain Reefs · QLD
Offshore: 220 km · A sheltered lagoon of colourful coral and fish schools, recovering well from COTS damage.
15. Swain Reefs · QLD
Offshore: 200 km · A near-circular, coral-rimmed drowned sinkhole up to 295 m across and 40 m deep – one of the GBR's rare blue holes.
16. Swain Reefs · QLD
Offshore: 200 km · A 100 m-wide blue hole with sheer walls reported to plunge to 90 m – an expedition-only dive.

17. Far Northern Reef & Torres Strait · QLD
Offshore: 140 km · The 1791 wreck of the Bounty-hunting frigate HMS Pandora – a permit-only historic shipwreck at 30–33 m.

18. Townsville & Magnetic Island · QLD
Offshore: 120 km · Outer-edge reef facing the Coral Sea with caves, canyons, walls and swim-throughs in 20–30 m visibility.

19. Far Northern Reef & Torres Strait · QLD
Offshore: 120 km · The world's largest green turtle rookery – dozens of turtles per dive and a chance of tiger sharks on pristine outer reef.
20. Townsville & Magnetic Island · QLD
Offshore: 110 km · Drop-offs, pinnacles and coral gardens in clear outer-shelf water; a noted night dive for lobsters and flatworms.

21. Mackay · QLD
Offshore: 100 km · Mackay's best outer reef – walls, canyons and plateaus with barracuda schools, sharks and turtles in 15–25 m visibility.

22. Heron Island & Capricorn Group · QLD
Offshore: 96 km · A closed Scientific Research Zone and world-class reef research station – not open to recreational diving.

23. Townsville & Magnetic Island · QLD
Offshore: 95 km · Excellent western wall with soft corals and gorgonians, detached pinnacles near the AIMS weather station and usually clear water.

24. Townsville & Magnetic Island · QLD
Offshore: 90 km · Quiet mid-shelf reef near Wheeler with trevally schools and bommies on its exposed faces.
25. Lady Musgrave & Bunker Group · QLD
Offshore: 90 km · Shallow brain-coral gardens outside the Fitzroy lagoon, used as an easy second dive with a chance of mantas.

26. Lady Musgrave & Bunker Group · QLD
Offshore: 90 km · The Bunker Group's biggest reef: a navigable 6-10 m lagoon with a dozen sites, seahorses and more than a thousand resident turtles.

27. Lady Musgrave & Bunker Group · QLD
Offshore: 90 km · A huge coral-encrusted wall full of caves, large and small, dived as a gentle drift an hour from Heron.
28. Townsville & Magnetic Island · QLD
Offshore: 89 km · Scant remains of the Reef Princess, a timber dive boat lost at Wheeler Reef in a 1981 storm – a footnote to Townsville dive history.

30. Heron Island & Capricorn Group · QLD
Offshore: 85 km · The shallow coral-garden second dive on Heron's Sykes Reef trips, rarely visited and undisturbed.
The guide
The list is ordered by distance from the coast among sites recorded as expedition-only or rarely dived, so it is a list of Coral Sea reefs and the atolls off the Kimberley. That is fair: these are the most remote reefs in Australian waters, days from a port and further from a recompression chamber. But remoteness is not only distance. Bass Strait islands, the far south coast of Tasmania, the Great Australian Bight and the Nullarbor caves are remote in every practical sense and sit lower down only because they are near land.
Read the list alongside the under-the-radar ranking, which finds the quiet sites close to home, and the liveaboard category, which is how most divers actually reach the outer reefs.
The Cairns liveaboards run Osprey, Bougainville and Holmes reefs on three- to seven-night trips year-round, with the settled season from September to December. The reefs at the top of this list (Mellish, Lihou, Cato, Marion, Wreck Reef) need an expedition charter of ten days or more, typically out of Cairns, Gladstone or Bundaberg, and they are offered irregularly. Ask the Coral Sea operators about their long-range schedule a year ahead.
For the Rowley Shoals and Scott Reef, boats leave Broome from late September to November. Ashmore Reef is a Commonwealth reserve with permit access and no commercial diving. The Kimberley cruises visit the inshore reefs and the Lacepede Islands rather than the outer atolls.
The nearest chamber to the outer Coral Sea is Townsville, often more than 24 hours away by sea and aeromedical evacuation. Boats carry oxygen, and the good ones brief conservative profiles: no decompression, 30 m limits, long surface intervals, and no diving on the last day before a long steam. Diving insurance with evacuation cover (DAN or equivalent) is a booking condition on most vessels, and it should be. The safety guide covers what evacuation from remote Australia actually involves.
Editorial last reviewed September 2026. The list itself is regenerated from the directory daily.
Almost all need a liveaboard or expedition charter: Coral Sea boats from Cairns (September–December), Rowley Shoals boats from Broome (October–November), far northern reef expeditions in October–November, and Kimberley cruises in the dry season. Book months ahead and carry DAN cover.
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