Just over an hour north of Sydney lies one of Australia's most extraordinary scuba diving experiences — the ex-HMAS Adelaide, a 138-metre-long guided missile frigate transformed into a thriving artificial reef off the Central Coast of New South Wales.

Since her scuttling in 2011, she has become a magnet for marine life, macro photographers, wreck enthusiasts, and thrill-seeking divers alike.

Whether you’re a newly minted Open Water Diver  advancing your skills or a seasoned tech wreck adventurer, the Adelaide offers a smorgasbord of unforgettable dives. Here are the seven best dive sites on the ex-HMAS Adelaide that will ignite your underwater imagination.

During a ferocious storm in June 2024 — followed by another powerful system in July — the ex-HMAS Adelaidesustained significant damage. The once-intact superstructure was torn from the main deck and now rests, rather unceremoniously, on the sandy seabed below. While this dramatic shift marked the end of the ship’s upright profile, it has completely transformed the site into a more expansive and intricate dive experience. The wreck now offers even more hiding places for marine life and endless new passageways for divers to explore.

The Adelaide has evolved — no longer just a warship-turned-artificial-reef, but now a dynamic, ever-changing underwater playground. Here are a few standout dive sites that will fire your imagination and keep divers returning time and again.

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1. The Bridge

Start your exploration with the commanding structure that once controlled the ship — the bridge. Perched midship nearly upside down and easily accessible at around 23 metres, this area offers a striking silhouette against the blue. As you hover over the command deck, imagine officers barking orders during naval manoeuvres. Now, instead of sailors, it’s the vibrant swirl of yellowtail scad, old wives, and batfish that dominate the scene.

Swim-throughs around the bridge windows make for excellent photos. Keep an eye out for wobbegong sharks dozing in the shadows, and don’t forget to shine your torch inside for lurking lionfish. 

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2. The Helicopter Hangar

Head aft and you’ll find the wide, open hangar bay lying sideways down, on the port side where Seahawk helicopters were once stowed. This cavernous space now hosts schools of bream and sweep, creating a cathedral-like experience as natural light pours through the overhead grating.

Penetration divers can safely enter the hangar through large openings, making it a perfect introduction to wreck penetration. The hangar is also a favourite haunt of massive dusky flathead and the occasional curious cuttlefish.

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3. The Missile Launcher

Bow to the thrill-seekers — the Adelaide’s missile launcher hole is a massive round circle  in the forward deck and offers one of the most iconic photo ops of any wreck dive in Australia. The structure teems with growth — sponges, ascidians, and feather stars cling to the deck area surrounded by beautiful Cauliflower soft corals covering the entire deck area.

Looking up from the missile hole with the sun behind a diver swimming above you, it’s a prime scene for wide-angle photography. This site is often surrounded by massive kingfish patrolling their metal kingdom. 

4. The Operations Room

Ready to go deeper? At approximately 28 metres, the operations room is an eerie time capsule. Dials, conduit lines, and the skeletal remains of radar and sonar control panels are still visible. Divers qualified for deeper penetrations can explore the area through designated entry points.

This is where the real history echoes — imagine the cold hum of electronics monitoring potential threats now replaced by curious eastern blue gropers and sea slugs exploring with equal curiosity.

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5. The Smoke Stack and Mast

The structure is now lying sideways on the sand and completely encrusted with vibrant filter feeders, and often blanketed by clouds of juvenile fish using the vertical sanctuary to escape predators.

Moray eels peek from vent holes, while bronze sweep shimmer like confetti in the sunlight. This area offers a great finale to a deeper dive.

The main mast now laying down on the sand in all its glory- a magnificent site, covered in more colourful anemones and soft corals.

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6. The Starboard Hull Swim-Throughs

If you're up for adventure, explore the series of swim-throughs that run along the ships hull. These passages, widened during the scuttling process, are diver-safe and allow a thrilling journey through shadowy corridors now home to painted crayfish and delicate nudibranchs.

The contrast between rusting steel and explosive marine colour is breathtaking — walls lined with pink soft corals and delicate bryozoans create a surreal, otherworldly experience.

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7. The Stern and Propeller Shafts

Rounding out the list is the massive stern section. Although the propellers were removed before scuttling, the shafts remain, cloaked in marine life and offering a ghostly reminder of the ship’s power. This area sits in deeper water (up to 35 metres), making it ideal for Advanced and Deep certified divers.

It’s not unusual to encounter schools of large trevally or even eagle rays cruising by. The structure offers dramatic lighting and framing, especially on clear visibility days.

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Bonus Tip: Dive the Adelaide at Night

If you’re truly brave and Advanced certified, experience the ex-HMAS Adelaide under the stars. At night, the ship comes alive in a completely different way — with crustaceans scuttling along the decks, bioluminescent flashes, and the odd squid darting in and out of passageways. The silence and shadows lend an almost sacred atmosphere to this submerged cathedral of steel.

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One Ship, Endless Adventures

The ex-HMAS Adelaide isn’t just a dive site — it’s an evolving reef ecosystem, a historical monument, and an underwater playground all in one. Whether you’re looking for macro photography, eerie interiors, vibrant marine life, or just a unique adventure, there’s a site on this wreck for every diver.

Remember to dive with a certified centre like Central Coast Divers to ensure safety, expert knowledge, and insider tips on where to find the elusive creatures that call the Adelaide home.

Ready to dive into history? Suit up and descend into the legends resting just off our coast.

Let’s go diving!