The aircraft are the most photographed part of the Cochrane Artificial Reef. Marinelife.org.au and Tourism Queensland list two Mohawk aircraft and a King Air among the structures sunk here, and GoodDive records the 'Two Mohawks' site as sitting in 16-18 m, placed in 1996. The Mohawk was a twin-turboprop military observation aircraft; a pair of retired airframes were stripped and sunk to create habitat and a novelty for divers, with the smaller civilian King Air added later.

Aircraft on sand make excellent dives because they are compact enough to see completely, with recognisable shapes – wings, engine nacelles, tails and cockpits – that give a wide-angle photographer something to work with even in modest visibility. They are now covered in sponges and small corals and have become home to fish. GoodDive mentions grouper, turtles and large rays at the Mohawks, and the Cochrane reef as a whole is known for friendly estuary cod and a resident Queensland groper family.

The depth sits at the edge of Open Water limits, so Open Water divers need to watch their gauges; Advanced divers with nitrox will get a comfortable 40 minutes. Visibility is the key variable – on a clear winter day with 12 m or more, the aircraft are superb; after rain they can be ghostly shapes in green water.

It suits photographers, aviation enthusiasts and divers who want something different from the barges. Treat the airframes gently: thin aluminium skin is easily damaged, and fishing line tends to snag on the tail surfaces.

Cochrane Artificial Reef lies about 3 nautical miles off the rocky Woongarra coastline east of Bargara. Charter and private boats launch at the Burnett Heads boat ramp beside the Port of Bundaberg (15 km north-east of Bundaberg on Burnett Heads Road; large trailer park, toilets). From the Burnett River entrance it is a short run south-east – roughly 20-30 minutes in a small boat.

The reef covers an area of about 400 x 800 m, and each structure has its own GPS mark, so boats either pick up a buoy where one is present or anchor in sand beside the target structure (never on the wreck). Bundaberg Aqua Scuba runs boat dives here when the weather allows; others come by private boat.

The reef is in open water off the Woongarra coast, partly sheltered from southerly ocean swell by K'gari but exposed to south-east trade winds and north-easterly sea breezes. Operators generally want winds under about 15 knots and seas under 1 m. Visibility averages 8-12 m and is best in winter (May-September) with light westerlies; it falls sharply after heavy rain as the Burnett and Elliott rivers flush brown water along the coast, typically in the December-March wet season.

Tidal current is usually mild but can run on big spring tides – dive around slack water on neaps for the clearest, calmest conditions. Manta rays pass through in winter.

Descend the line onto the sand beside the aircraft at 17-18 m. Circle each airframe slowly – wings, tail and cockpit – looking under the fuselage for rays and cod. If the aircraft are close together, use a compass bearing to swim between them.

Return to the line on a third of your gas and complete a safety stop.

Bundaberg Aqua Scuba (Bourbong St, Bundaberg) – boat dives to Cochrane Artificial Reef when weather permits, typically weekends or on demand; otherwise private boats from Burnett Heads. Fishing charters use the reef heavily.