The ex-HMAS Hobart is one of Australia's great wreck dives and South Australia's premier boat dive. Launched in Michigan in 1964 and commissioned in Boston in 1965, the 133 m, 4,500-tonne Charles F. Adams-class guided missile destroyer served the Royal Australian Navy for 35 years, including three Vietnam deployments – during one of which, in 1968, she was mistakenly struck by US aircraft and two sailors were killed.

After decommissioning she was gifted to South Australia and prepared at Port Adelaide for scuttling: contaminants were removed, doors and hatches taken out, corridors widened, sharp protrusions removed and some entrances sealed, while keeping her character as a fighting ship. She was scuttled on 5 November 2002 in Yankalilla Bay. The ship sits upright on sand in 30 m, with her superstructure rising to within about 5-8 m of the surface and the main deck around 15 m.

The bow rises like a knife toward the surface, the sonar dome sits near the seabed at 30 m, and the gun mounts and bridge remain. Large openings cut in the hull let in light and allow access to the interior, and the Hobart is the only artificially prepared naval wreck in Australia where divers can reach the engine room. Crew quarters with bunks, and even toilets, remain.

More than two decades of growth have coated the hull in colourful sponges and algae, and the no-take sanctuary zone has produced a staggering variety of fish – bullseyes, snapper, flathead, blue devils (often inside), old wives and morwong. For 20 years divers needed a DEW permit, but the 550 m protected-zone permit requirement was removed in 2023; the 2025 code of conduct requires no permit for recreational divers and instead sets depth and penetration limits by certification. The Hobart rewards repeat visits and is best for Advanced divers and above; wreck-trained divers get the most from it.

Boat access only. Charters and private boats depart from Wirrina Cove (Marina St Vincent, also called Sunset Cove), about 1 hour 15 minutes' drive south of Adelaide via Main South Road past Normanville; the marina has a boat ramp and a fuel jetty from which charters load. The run to the wreck is about 10-20 minutes.

A restricted area of 0.5 nautical miles surrounds the wreck: anchoring is prohibited except at the permanent mooring facilities. Boats tie up to the red buoys (attached to concrete blocks on the seafloor); the white buoys are attached to the wreck and are for divers' descent and ascent lines only – boats must not use them as their primary mooring.

Tidal current is the dominant factor: local sources describe very strong tidal currents across Yankalilla Bay, and the Hobart should be dived only around slack water, ideally on neap 'dodge tides' when the gulf's tide barely moves. Check a dodge-tide calendar before booking. The wreck is exposed to westerly, south-westerly and northerly winds; easterlies and light southerlies give the calmest crossing.

Visibility is variable – often milky outside with current-driven water, sometimes clearer inside the hull – and is best in late summer and autumn.

Descend a white diver line to the superstructure (5-8 m tops, main deck about 15 m). On a first dive stay outside: tour the bridge, gun mounts and missile launcher along the upper deck, dropping to the sand at 30 m only if gas and no-deco time allow. Wreck-trained divers can enter the hull through cut openings to the crew quarters and the engine room.

Return to the same white line and ascend, doing the safety stop on the line with the current in mind. Most divers need several dives to see the whole ship.

Code of conduct (2025): Open Water divers outside the wreck to 18 m; Advanced Open Water outside to 30 m; wreck, technical or cave trained divers may penetrate within their training. EANx 28-32 extends bottom time; penetration needs a continuous guideline, redundant lights and gas reserves; deco diving should be planned around slack. Rebreathers well suited.

Divers under 18 must be supervised by qualified adults.

Adelaide Scuba (Glenelg North) – regular Hobart double-dive days from the Wirrina Cove fuel jetty; Underwater Sports (Edwardstown) – scheduled Hobart trips on its own boat; other Adelaide shops and clubs run periodic trips; private boats from Wirrina Cove. Commercial operators require a marine park commercial tour operator permit.