The Blue Lagoon on Lizard Island is a shallow, sheltered body of water that Queensland Parks describes as offering layered coral formations and sandy patches – one of the two primary snorkelling destinations the park highlights, alongside the Clam Gardens. It is reached on foot by the Blue Lagoon walking track, which Spirit of Freedom's island guide lists as 455 m return and about 40 minutes. The lagoon is protected from waves by the surrounding islands and reef, so the water is usually calm.

Coral grows in layers – tiers of plate and branching corals – separated by patches of white sand that give the lagoon its blue colour. Reef fish shelter among the corals, and turtles, rays and small reef sharks may wander in. Giant clams also occur in the lagoon area.

The shallow depth makes the Blue Lagoon ideal for snorkellers, including families. Scuba divers would find it too shallow for a conventional dive, but it is suitable for a relaxed shore snorkel. As with other Lizard Island sites, tidal state matters: at low tide parts of the lagoon may be very shallow, so plan for mid to high tide.

Queensland Parks warns visitors to be aware of wind and currents, and to ask at the resort's watersports centre if in doubt. Stingers and crocodiles are also possible. Depths and exact coordinates are not published.

The Blue Lagoon is a quieter alternative to Watsons Bay and a good spot for those who enjoy combining a short walk with a snorkel. Its name is shared with sites at Agincourt, Opal and Thetford reefs, so be specific when discussing it with operators.

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.

Walk the Blue Lagoon track (455 m return), enter from the beach near high tide and snorkel over the layered coral and sand patches in 1–3 m, staying inside the lagoon and away from any channels where the tide runs.

No operator required – reached on foot by the Blue Lagoon track from the resort/airstrip area; resort guests may also be taken by boat.