Meet the site
Acropolis is a site on Opal Reef that Scuba IQ describes as a shallow coral theatre leading to a wall that circles toward the northern channel sites, and recommends for nudibranch hunting. The coral theatre is a shallow, amphitheatre-like area of hard corals – the name nods to Acropora, the branching and plate coral genus, as well as to the ancient Greek citadel. It is bright, colourful and full of reef fish. From there, a wall curves around the reef towards the channels at the northern end, offering a different habitat with overhangs, crevices and encrusting life. The wall is where nudibranchs are found. These colourful sea slugs graze on sponges, hydroids and ascidians, and a slow search along the wall can turn up several species. Other macro life – flatworms, shrimps and small crabs – is also common. Scuba IQ does not publish depths; the shallow theatre is probably within 3–8 m, while the wall likely extends to 15 m or more. Visibility is typically 15–30 m. The site suits all levels, especially those interested in macro life, and is best dived slowly. Acropolis offers a combination of shallow coral scenery and macro-rich wall diving, and its connection to the northern channel sites means guides can adapt the route to conditions. Divers heading towards the channel should stay close to the guide, as current can pick up near the gaps between the Opal reef sections.
What you might see
Nudibranchs (several species), flatworms, shrimps, small crabs, reef fish, Acropora plate and branching corals
Location
A shallow coral 'theatre' on Opal Reef leading to a wall that circles towards the northern channel sites.
Facilities nearby
Departs Crystalbrook Superyacht Marina, Wharf Street, Port Douglas – car parking, toilets, cafes and restaurants at the marina; dive shops in town for gear hire and air
Before you make plans
Conditions, access and operator schedules can change. This is a location guide, not a dive plan. Ask a local operator about current conditions and suitability for your training and experience.
Sources & further reading
scubaiq.com.auRecord updated 26 Sept 2026. Source claims are being reviewed.