Curtin Artificial Reef is one of Brisbane's best and busiest dives, and the world's first diver-built artificial reef. The Underwater Research Group of Queensland began it in 1968 by sinking an old dredging barge off the western side of Moreton Island, and over the next 30 years the club added more than 25 vessels. Today it covers roughly 400 x 120 m and holds over 30 shipwrecks – tugs, barges, whale chasers, a ferry, a trading vessel and a yacht – along with a Brisbane tram, car bodies, concrete pipes, steel pontoons, buoys and tyres, in depths from 12 to 30 m.

It is named after Frank Curtin, a key figure in the project. The major wrecks include the 40 m coastal trader Lady Norman, the largest vessel, sitting about 50 m west of the others; the 35 m tug Melbourne near the centre; the 32 m coal and gravel barge Barrambin; the 50 m coal barge Bremer; the tug Loevenstein; the gravel barge Estrella del Mar; the Amsterdam barge; and the Cairncross drydock gate. Several wrecks can be penetrated by trained divers.

The fish life is the reason Curtin is famous. Dozens of Queensland groupers live on the reef, typically 1-2 m long and occasionally up to 3 m, alongside barracuda, giant trevally, yellowtail kingfish, cobia, goldspotted grouper, turtles and stingrays. The hulls support butterflyfish, angelfish, sweetlips, Moorish idols, lionfish and blennies, while painted frogfish, ornate ghostpipefish, blackspot waspfish and leaf scorpionfish reward macro hunters.

Nudibranchs, octopus, squid and spiny lobster are common. Because it is tidal, the dive is planned around the high-tide slack, and even then there is more to see than one visit allows. It suits everyone from supervised open-water divers on the shallower wrecks to wreck-trained divers exploring interiors.

Boat access. Brisbane charters (Brisbane Scuba from Manly Boat Harbour; Go Dive Brisbane; Brisbane Dive Academy) cross Moreton Bay to the western shore of Moreton Island in roughly 45-60 minutes. Private boats launch at Scarborough Boat Harbour, Manly or the Port of Brisbane-area ramps (Wynnum, Victoria Point for the south) and run north-east across the bay; the run is sheltered from ocean swell but can be choppy in fresh south-easterlies.

Divers with 4WDs can also take the MICAT vehicle barge from the Port of Brisbane to the Tangalooma area and drive the western beach (QPWS vehicle permit required). Curtin lies just offshore north of Cowan Cowan; there are public moorings on the reef.

The site is tidal: Moreton Bay's tides push strong currents along the western side of Moreton Island, so dive at the slack on the top of the tide – roughly 30-60 minutes after high water – when the current eases and the cleaner incoming water gives the best visibility. Avoid big spring tides and the ebb, which brings turbid bay water. Curtin is inside the bay and sheltered from ocean swell, but strong northerly winds put chop onto the site and westerly winds over about 20 knots make the crossing wet.

Visibility averages about 10 m but ranges from 6 to 30 m; it is clearest after southerly winds and on a high tide that brings in oceanic water through the North West Channel, and worst after heavy rain or on a big ebb.

Pick up a mooring on a target wreck at slack high water. Descend the line, explore that vessel and, if time and current allow, move to an adjacent wreck – most are close together. Keep an eye on the tide turning and return to the line with enough gas to ascend in a building current.

It takes about a dozen dives to see the whole reef.

Several wrecks are penetrable – wreck training, lines and lights required. Nitrox useful for the 20-30 m wrecks. Carry a knife for fishing line.

Brisbane Scuba (Manly) – regular Curtin days and double dives; Go Dive Brisbane and Brisbane Dive Academy – frequent trips; Supercat Charters – charter. Also heavily used by Brisbane clubs (URGQ, UniDive, Brisbane Sub-Aqua Club).