Situated north of Cooktown, close to the Queensland cape, Great Detached Reef is a large complex of several reefs sitting on an old fossil mountain range. With roughly 46 kilometres of edge, wall diving is spectacular here, with steep cliffs dropping down to over 400 metres and small caves scattered across the reef walls.

Barracuda, trevally and sharks, along with schools of basslets, fusiliers and sometimes blue-lined snapper, peer over the edges of the Great Detached Reef, while moray eels, lobster, shrimp and nudibranch pocket the coral and rock surfaces. Large potato cod as well as manta rays and turtles are also frequent visitors.