Cobia Hole is a small dive site about 10 minutes from Lizard Island, described by the resort as boulders and rocks stacked on one another with an incredible abundance of fish. It requires a smaller vessel and is a dive-only site – there is no snorkelling, as the structure lies at 14–18 m. The stacked boulders create a maze of gaps, caves and overhangs that shelter a remarkable number of fish for such a small site.

The resort lists schools of barracuda, giant Queensland groupers, clown anemonefish, octopus, tawny nurse sharks and eels. The giant groupers are the stars – huge fish that can exceed 2 m and 300 kg, often seen hanging in the gaps between boulders. Tawny nurse sharks rest under overhangs during the day, and octopus hide in crevices.

Barracuda school above the boulders, and anemones with clownfish grow on the rock surfaces. Eels peer from holes. The fish density is the main attraction – a small pile of rocks acting as an oasis on the seafloor.

Because the site is compact and deep, divers spend the whole dive at 14–18 m, so no-decompression limits must be watched. Current can run over the site. It suits open water divers comfortable at that depth; the resort's guides lead dives.

The name refers to cobia, a large pelagic fish that may once have been common here. For resort guests who dive, Cobia Hole offers a quick, fish-packed dive close to the island, and a chance to see giant groupers without a long boat ride.

Lizard Island lies about 27 km off the Cape York coast and roughly 240 km north of Cairns. Most visitors fly: resort guests take the scheduled light-aircraft transfer from Cairns (about 1 hour) to the island airstrip, and campers can charter flights or arrive by private boat. There is no public ferry.

The dive and snorkel sites are reached by the Lizard Island Resort dive centre's boats (reserved for resort guests) or by liveaboards – Spirit of Freedom uses Lizard as the fly-in/fly-out changeover point for its 3- and 4-night trips, and Mike Ball's Spoilsport visits on Cairns-based expeditions. Campers at Watsons Bay must carry gear about 1.2 km from the airstrip and bring all supplies.

Lizard Island sits in the path of the south-east trade winds, which blow strongly (often 20–30 knots) from about April to September. The island's western and northern bays (Watsons Bay, Mermaid Cove, Anchor Bay) are sheltered, but open-water crossings to the outer ribbon reefs (Cod Hole, Dynamite Passage, No Name) can be rough and are cancelled in strong winds. October–December usually brings lighter winds and the clearest water; the wet season (December–April) brings northerly winds, storms, cyclone risk and marine stingers (November–May).

Tides are significant – shallow bay snorkelling (e.g. Clam Gardens) is best around high tide. Visibility around the island is typically 10–20 m; the outer ribbon reefs often exceed 25 m.

Descend directly to the boulder pile at 14–18 m and circle it slowly, checking the gaps between boulders for groper, nurse sharks and octopus; watch the water column for the barracuda school. Ascend on the anchor or with an SMB for the safety stop.

Lizard Island Resort dive centre – dive-only site visited with a smaller vessel, for resort guests; not a snorkel site.