Neptune Islands

The Neptunes are Australia's only licensed great white cage-diving grounds, two clusters of granite islands where long-nosed fur seals breed and the sharks that hunt them patrol. Surface cages hang off the stern on hookah air, open to anyone who can climb a ladder, while one long-running operator lowers a cage to the seabed so certified divers can watch whites cruise at their own level, unhurried and enormous. Sharks are present year-round without being guaranteed on any given day; the cooler months are often quoted for larger females. Between passes, the seals themselves supply the comedy the sharks decline to provide.

The moment you come for: Great whites from surface and seabed cages, fur-seal colonies, professional licensed operation

Topography: Granite island group over sand and reef, dived from anchored vessels

Entry: Full-day and multi-day licensed charters from Port Lincoln anchor near the fur-seal colonies; all in-water time is inside cages.

Hazards: Cold water, swell on the crossing, and the obvious: follow cage protocol exactly and keep all limbs inside.

Permits & rules: No independent diving; access is exclusively through licensed cage-dive charters from Port Lincoln.

Conservation: Cage diving here is limited to a small number of licensed operators under South Australian management, with rules on attractant use and shark interaction.