Hanging Rock is regarded by Scuba World as one of the best sites on the Gneering Shoals and is a regular on Sunreef's rotation. Scuba World describes 'an enormous rocky outcrop which overhangs a sandy trench below', and Sunreef gives the dimensions: a lively 5 m wall about 50 m long, with its top at 12 m – shallow enough for all qualification levels, including divers in training.

The overhang is the feature. Its underside is carpeted with orange sun corals and shelters small moray eels, while the wall face carries what Sunreef calls some of the largest plate corals on the local reefs. Because the trench floor is sand, the structure stands out clearly even in modest visibility.

Fish life is abundant. Sunreef lists clownfish, many nudibranch species, eagle rays, moray eels, barracuda, turtles and reef fish, and Scuba World calls it 'a photographer's delight' with abundant tropical fish. The overhang offers some shelter from surge, which helps on days with a little swell.

Hanging Rock is short and easy to navigate – follow the wall one way, return the other – which makes it popular with newer divers and underwater photographers alike. Combine it with Nurse Rock or the Caves on a Sunreef double dive, or with the Brisbane when the wreck's conditions allow. The sandy trench is a good place to settle and look up at the overhang for photographs – with good buoyancy you can frame the sun corals against the surface light without touching the reef. Keep clear of the plate corals, which break easily under a careless fin.

Mooloolaba's dive boats leave from The Wharf on the Mooloolah River (Parkyn Parade, Mooloolaba), about 1.5 hours' drive north of Brisbane via the Bruce Highway and Sunshine Motorway. Scuba World's shop is about 40 m from its boat, with 100+ free all-day parking spaces nearby; Sunreef departs from the same precinct. Boats run down the calm river, cross the Mooloolah River mouth beside Point Cartwright and head north-east to the reefs – about 15 minutes to the Inner Gneerings and Mudjimba Island.

Private boats can launch at the Mooloolaba (Parkyn Parade/Lions Park) ramps. Operators choose between sites on the day according to swell and current.

The Mooloolaba reefs are open-ocean sites with no shelter from the south-east trade winds or easterly swell. Operators generally cancel when winds exceed about 20 knots or swell makes the river-mouth crossing and moorings unsafe; they confirm trips by email and text around 3.30 pm the day before. Northerly winds (common on summer afternoons) also make the reefs choppy, so morning trips are more reliable.

Visibility averages about 12 m offshore (range 3-30 m) and is clearest after southerly winds and in winter; it drops after easterly blows and heavy rain. Winter (June-October) brings 19-21°C water, grey nurse sharks and humpback whales; summer (November-May) brings 25-27°C water, leopard sharks and lower visibility.

Descend to the top of the wall at 12 m, drop into the sandy trench at about 17 m and swim the 50 m length of the overhang, looking up into the sun corals and plate corals and into the crevices for morays. Return along the top of the wall. Sunreef plans 50 minutes or 50 bar, whichever comes first.

Sunreef Mooloolaba – double reef dives most days, rotating between Mudjimba Island, Nurse Rock, Hanging Rock and Caves; Scuba World Mooloolaba – reef double dives rotating through the Gneering Shoals and Mudjimba sites; SubSurface Scuba – Sunshine Coast reef double dives.