MacGillivray's Reef – also known as Banks Bank – is a coral sand cay reef about 20 minutes from Lizard Island. The resort describes a large reef system with anemonefish, schooling reef fish, moray eels, reef sharks, nudibranchs, flatworms and blue-spotted lagoon rays, as well as birdlife on the cay: noddy terns, brown boobies and bridled terns. The reef surrounds a small sand cay that is used by seabirds for roosting and nesting.

Underwater, the reef slope drops from about 7 m to 25 m, offering a range of depths for divers of different levels. Schooling reef fish swarm over the reef, reef sharks patrol the edges, and moray eels peer from holes. The smaller life is rich: nudibranchs and flatworms on the reef surfaces, anemones with anemonefish, and blue-spotted lagoon rays on the sand.

The site is close enough to the island for a half-day trip, making it a popular choice for resort guests. Divers can explore the reef slope, while snorkellers can enjoy the shallower sections near the cay, depending on conditions. MacGillivray Reef is named after the naturalist John MacGillivray, who visited the area aboard HMS Rattlesnake in the 1840s.

Visitors should not land on the cay during bird-nesting periods, and should keep noise down near roosting birds. The combination of reef and birdlife makes this a varied outing. It suits divers of all levels, and the macro life will appeal to photographers.

Lizard Island is remote: the nearest recompression chamber is in Townsville, several hours away by aeromedical evacuation, so divers should dive conservatively, stay well within no-decompression limits and hold dive insurance that covers evacuation.

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 from the boat to the reef slope at 12–18 m and work along it, looking for moray eels, nudibranchs and flatworms, then ascend to the shallower reef top at 7–10 m where anemonefish and lagoon rays are common. Safety stop on the reef top.

Lizard Island Resort dive centre – daily boat dives and snorkel tours for resort guests only; liveaboards (Spirit of Freedom 3/4-night trips changing over at Lizard; Mike Ball Spoilsport) occasionally.