Depth is the number every diver asks first, and in Australia it runs from a 124 m sinkhole under a South Australian paddock to the 200 m dumping ground off Rottnest. Almost everything on this list is technical territory: decompression, mixed gas, cave or deep wreck training, and a local operator or club that knows the site.
The ranking is by the recorded maximum depth of the site. Many of these have shallower sections that recreational divers can enjoy; the site pages say where.
Updated daily from the directory. 25 sites listed.
1. Rottnest Island · WA
Rottnest Ships' Graveyard
Max depth: 200 m · The deep-water dumping ground west of Rottnest, home to technical wrecks in 30–200 m.
Our takeNot one dive but a scuttling ground: some 40 known hulls between 46 and 200 m in a few square kilometres off Rottnest. The Perth technical community has identified and filmed only a fraction of them. Everything here is trimix and a boat that can hold station in the swell.
2. Mount Gambier Sinkholes & Caves · SA
The Shaft
Max depth: 124 m · A 124 m deep sinkhole entered through a hole in a paddock. Advanced cave rating only.
Our takeThe reason Australia has cave-diving rules. Four divers died here in 1973, the CDAA was formed, and the site is now permit-only Advanced Cave. Entry is through a hole in a paddock barely wider than a diver in twinsets; the chamber below is 140 m long.
Sinkhole/CenoteMax 124 mExpert/TechnicalCave/Cavern certificationShore accessMore in Mount Gambier Sinkholes & Caves →
3. Wilsons Promontory · VIC
SS Federal
Max depth: 115 m · A collier lost with all hands in a 1901 gale and found by CSIRO sonar in 2019, lying broken in 115 m off Cape Conran – a protected zone and not a practical dive.
Our takeFound by CSIRO's RV Investigator in 2019 and dived by a handful of teams since. At 115 m off Cape Conran it is a two-hour decompression for a few minutes on the wreck, and it lies inside a protected zone that needs a permit.
4. Mount Gambier Sinkholes & Caves · SA
Piccaninnie Ponds – The Chasm
Max depth: 110 m · Hanging over a 100 m+ spring-fed slot in 40 m-plus visibility – the signature Mount Gambier image.
Our takeThe Chasm is a slot in the limestone that keeps going: 100 m plus, in water so clear that hovering at the lip at 35 m feels like standing on a balcony. Only the top of it is open to recreational cave divers with a permit.
Sinkhole/CenoteMax 110 mAdvancedCave/Cavern certificationShore accessMore in Mount Gambier Sinkholes & Caves →
5. Port Phillip Heads · VIC
Trimix Corner / Entrance Deep
Max depth: 103 m · The descent point for Entrance Deep, Victoria's deepest known dive at 103 m in the drowned Yarra channel inside the Heads – black, barren, treacherous and for expert trimix teams only.
Our takeVictoria's deepest known dive is the drowned bed of the ancient Yarra where it cut through the Heads. Black, tidal and featureless below 60 m; it is dived for the number, on slack water, by very experienced Melbourne technical divers.
6. South West Rocks · NSW
MV Fairwind wreck
Max depth: 87 m · A 1950 Army lighter lost with all hands in a cyclone, undiscovered until 2009 and now one of Australia's premier deep technical wreck dives, sitting largely intact at 87 m.
Our takeAn Army lighter lost in 1950 and found in 2009, intact at 87 m off South West Rocks. The local technical operators run it in the winter calm; it is arguably the best-preserved deep wreck on the east coast.
7. Surf Coast & Great Ocean Road · VIC
City of Rayville
Max depth: 82 m · The first American merchant ship lost in WWII, intact and upright in 82 m off Cape Otway – Victoria's premier deep technical wreck.
Our takeThe first American merchant ship lost in the Second World War, mined off Cape Otway in November 1940 and intact in 82 m. Victoria's premier deep wreck; the Apollo Bay technical boats run it in calm autumn weather.
8. Port Phillip Heads · VIC
HMAS Bayonet
Max depth: 82 m · An Attack-class patrol boat scuttled in 1999 and found in 2001 – upright and clean in 82 m off Cape Schanck with waterline marks still readable; a rare rebreather expedition dive.
Our takeAn Attack-class patrol boat scuttled in 1999 and only found two years later, sitting upright and almost clean in 82 m off Cape Schanck. Small enough to see whole in one dive if the plan is tight.
9. Wilsons Promontory · VIC
TSS Kanowna
Max depth: 82 m · A 126 m WWI hospital ship and coastal liner lost in fog in 1929, found in 2005 and lying largely recognisable in 80–82 m of clear Bass Strait water – Victoria's deepest regularly attempted wreck.
Our takeA 126 m hospital ship and coastal liner lying in 80 m of some of the clearest water in Bass Strait. Discovered in 2005; the bow, bridge area and holds are still recognisable and the visibility can exceed 30 m.
10. Port Phillip Heads · VIC
SS Alert
Max depth: 75 m · An upright, largely intact 1877 iron steamer in 75 m, lost with 15 lives in 1893 and found by Southern Ocean Exploration in 2007; permit-only protected zone.
Our takeAn 1877 iron steamer standing upright in 75 m off Cape Schanck, with 15 lives lost in the 1893 gale. Found in 2007 and now a permit-only historic shipwreck; the funnel, mast and deckhouses survive.
11. Port Phillip Heads · VIC
Don Diego
Max depth: 72 m · The oldest hull in the Graveyard – an 1855 Greenock-built iron barque and coal hulk scuttled in 1916 – bow and stern rising 4 m from the sand in 70–72 m near the shipping lanes.
12. Tasman Peninsula · TAS
SS Tasman
Max depth: 72 m · Rarely seen 1883 steamer at 70 m beneath the Hippolyte Needle – a serious technical expedition target.
13. Port Phillip Heads · VIC
Brunette
Max depth: 70 m · An 1859 Thames-built iron barque and coal hulk – the first vessel scuttled in the Graveyard (1913) – found by Southern Ocean Exploration in 2006 lying in 70 m.
14. Wilsons Promontory · VIC
South East Point (Wilsons Promontory Lighthouse)
Max depth: 70 m · Granite walls plunging to 70 m with caves and swim-throughs directly beneath the Wilsons Promontory Lighthouse; the eastern Prom's deep wall.
15. Port Phillip Heads · VIC
John Nimmo
Max depth: 68 m · An 1887 Footscray-built Harbour Trust bucket dredge standing 4–5 m proud in 68 m – possibly the best-preserved wreck in the Graveyard, with superstructure to explore.
16. Port Phillip Heads · VIC
North Wall Corner
Max depth: 66 m · The 90-degree corner of Lonsdale Wall: towering split faces on two sides dropping from 19 m to 66 m, with blue devils and the occasional blue groper in the cracks.
17. Albany & Great Southern · WA
Football Field (King George Sound)
Max depth: 66 m · Deep, rarely visited canyons and bommies to 66 m with pristine sponge gardens, huge gorgonians and black coral.
18. Phillip Island & Western Port · VIC
TSS Coramba
Max depth: 66 m · A Western District coastal steamer lost with all 17 hands in a 1934 storm, found by Southern Ocean Exploration in 2011 lying almost upside down in 66 m south of Seal Rocks.
19. Mount Gambier Sinkholes & Caves · SA
Kilsby Sinkhole
Max depth: 65 m · The open-access showpiece of the Mount Gambier sinkholes: 65 m deep, clear as air, recreational depth on the upper platforms.
Sinkhole/CenoteMax 65 mIntermediateTechnical (decompression)Shore accessMore in Mount Gambier Sinkholes & Caves →
20. Port Phillip Heads · VIC
Nepean Wall
Max depth: 65 m · The vertical Nepean side of The Rip: a boomerang-shaped trench whose northern wall drops from 18 m to 65 m through large caves and undercuts, dived on the ebb-to-flood turn so the tide carries you home.
21. Tasman Peninsula · TAS
Hippolyte Rocks
Max depth: 65 m · Remote seal-colony islets with bull kelp shallows, sponge reefs from 30 m and huge fish schools.
22. Atherton Tablelands · QLD
Lake Eacham
Max depth: 65 m · A rainforest-fringed volcanic crater lake with sunken trees, turtles and submerged boats at 25 m – Queensland's classic altitude and freshwater dive.
Freshwater Lake/RiverMax 65 mIntermediateTechnical (decompression)Shore accessMore in Atherton Tablelands →
23. Port Phillip Heads · VIC
Outer Corsair Wall
Max depth: 65 m · The outermost Nepean-side wall: ledges, caves and drop-offs from a 10 m kelp top to 65 m facing Bass Strait, with the clearest water at the Heads and a very short slack.
24. Atherton Tablelands · QLD
Lake Barrine
Max depth: 65 m · The Tablelands' largest crater lake – deep, rain-fed and rarely dived, beside a 1926 teahouse.
Freshwater Lake/RiverMax 65 mIntermediateTechnical (decompression)Shore accessMore in Atherton Tablelands →
25. Wilsons Promontory · VIC
Skull Rock
Max depth: 65 m · Sheer granite walls dropping past 65 m beneath the Prom's landmark sea-cave island, in the clearest water in Victoria, with fur seals for company; the state's premier remote wall dive.
The guide
How to read this list
Maximum depth is the number a database can sort by, but it is not what makes these sites hard. Three things are: the environment (open ocean over 80 m, a sinkhole shaft, a tidal channel), the logistics (a boat that can find and hold a mark, a permit, a cave rating) and the distance to a chamber. Almost everything above 60 m on this list is dived by a small circle of technical divers and clubs, on rebreathers or open-circuit trimix, in specific weather windows.
The recreational reader should look at the shallow ends. Piccaninnie Ponds, Kilsby and Ewens Ponds put Open Water divers over water that is 60 to 100 m deep without taking them past 20 m. The Kanowna and Federal have no shallow options, but the Port Phillip Heads walls that lead down to Trimix Corner start at 12 m.
Where the deep water is
Victoria dominates. Bass Strait is shallow but the shipping lane past the Heads, Cape Schanck and Cape Otway has claimed liners, colliers and warships in 70 to 115 m, and Melbourne has the most active technical wreck community in the country to find them. South Australia's Limestone Coast supplies the sinkholes: the Shaft, the Chasm and a dozen deep cave systems, all managed by the CDAA. Western Australia has the Rottnest graveyard and the Nullarbor caves; New South Wales has the Fairwind and a run of 60 m-plus wrecks off Sydney and South West Rocks.
Queensland barely features, which surprises people. The reef is shallow, the deep walls of the Coral Sea drop from 20 m to 1,000 m without a floor to record, and the state's deep wrecks (the Yongala at 30 m, the Brisbane at 28 m) are recreational. Deep in Queensland means offshore, not down.
Training and access
Below 40 m is technical diving by every agency's definition: decompression procedures, redundant gas, helium below 50 to 60 m. The sinkholes add CDAA ratings (Deep Cavern, Cave, Advanced Cave), most of which take years. Many of the wrecks are protected historic shipwrecks or war graves with permit systems run by the state heritage office; the site pages say which. The technical diving section explains the courses, and the courses directory lists the centres that teach them.
Editorial last reviewed September 2026. The list itself is regenerated from the directory daily.
Frequently asked questions
What is the deepest dive site in Australia?
Rottnest's Ships' Graveyard holds wrecks down to 200 m, dived only by technical teams. The deepest sinkhole is the Shaft near Mount Gambier at 124 m; the deepest commonly dived wrecks are the Kanowna (82 m) off Wilsons Promontory and the Nord (42 m) in Tasmania.
How deep can a recreational diver go?
Recreational agencies cap depth at 40 m with the Deep Diver specialty, 30 m with Advanced Open Water and 18 m with Open Water. Beyond 40 m is technical diving.
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