Shark Alley is the reason many divers make the trip to Point Lookout in winter. On the eastern edge of Flat Rock, two sandy channels cut through the rock strata, and between June and October grey nurse sharks gather in them, sometimes a single animal, sometimes as many as fifteen circling slowly through the gutters. Manta Lodge points out that only about 500 grey nurse sharks remain on the east coast of Australia, making this one of a handful of places where divers can reliably see the species.

The dive runs from about 12 m on the reef top to 35 m in the deeper parts of the channels, and it is rated for advanced divers because of depth, exposure and the need for good buoyancy control near the sharks. Grey nurse sharks look fierce, with their ragged teeth, but they are placid, and the experience of hovering at the edge of a gutter while several sharks glide past at arm's length is one of the best big-animal encounters in Australian diving. The code of conduct matters: divers must not block the channels, chase or touch the sharks, and should stay beside the gutters rather than in them.

There is more than sharks here. Schools of rays, turtles, wobbegongs, groupers and pelagic fish use the channels and reef edges, and crayfish and crustaceans hide in the rock. Outside the shark season the site is still a good deep reef dive, but winter is when it earns its name.

It is best combined with a shallower Nursery or Manta Bommie dive.

Drive to Cleveland (about 40 minutes from Brisbane) and take the SeaLink vehicle ferry or a passenger water taxi across to Dunwich on North Stradbroke Island, then drive about 20 km (25 minutes) east to Point Lookout. Manta Lodge & Scuba Centre at Point Lookout runs the dives, beach-launching its boats and reaching the Point Lookout sites in roughly 5-15 minutes. Brisbane operators (Brisbane Scuba from Manly, Gold Coast Dive Adventures from Runaway Bay) also run occasional day trips.

Shark Alley is on the eastern side of Flat Rock, about 10-15 minutes from Point Lookout.

On the exposed eastern side of Flat Rock, Shark Alley is the first sub-site to become undiveable in south-easterly or easterly swell over about 1.5 m, which creates surge in the channels. Currents are minimal to medium. Winter – the shark season – often brings westerly winds and the best visibility (20-30 m), but south-easterly trade-wind spells and passing fronts can shut it down for days.

Descend the mooring, follow the guide to the edge of the channels and settle on the rock beside – not in – the gutters at about 18-24 m. Watch the sharks cruise past without blocking their path, then work back along the reef edge to the mooring.

Nitrox extends time at 20-25 m beside the gutters.

Manta Lodge & Scuba Centre – daily in the grey nurse season (June-October) when conditions allow; Gold Coast Dive Adventures and Brisbane Scuba – occasional trips.