Lost Canyons is listed by Scuba World as one of its Mooloolaba reef dive sites. No description has been published; the name points to canyon or gutter topography, which is characteristic of the Gneering reefs, but this is not confirmed by any source.

Like the other named sites off Mooloolaba, it sits on the Gneering Shoals reef system, which Scuba Diver Life describes as gutters, ledges, caves and pinnacles with coral gardens in 8-33 m, and Scuba World summarises its reef sites as mostly 15-20 m (range 12-35 m, average 18 m) with 'incredible macro life'. The rock is covered in a subtropical mix of algae, sponges, ascidians, soft corals and scattered hard corals. Typical residents across these reefs include butterflyfish, angelfish, wrasse, morwong, surgeonfish, moray eels, wobbegongs, turtles and rays, with some of the highest nudibranch diversity in Queensland; leopard sharks visit in summer and grey nurse sharks and humpback whales in winter.

Scuba World Mooloolaba includes the site in the rotation for its reef double dives, which run about 15-30 minutes from The Wharf and are chosen on the day according to swell, wind and current. Visibility is typically 8-15 m, best in winter after southerly winds. Mooloolaba operators confirm trips by email or text around 3.30 pm the day before, depending on sea conditions, and plan local reef dives to about 50 minutes or 50 bar, whichever comes first, with the surface interval spent on the boat. Open Water certification is the usual minimum for the reef sites.

Ask the dive crew for a site brief before descending.

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.

Follow the guide's brief. Typically descend the mooring or anchor line, explore into the current along the reef structure at 12-20 m, turn on a third of your gas and return to the line for the ascent and a safety stop.

Scuba World Mooloolaba – reef double dives rotating through its listed Gneering Shoals sites (weather permitting); Sunreef and SubSurface Scuba run similar local reef trips.