Neptune Islands is one of the few places in the world where you can dive with great white sharks from a cage. The site also draws bronze whaler and mako sharks, plus large colonies of New Zealand fur seals and Australian sea lions that regularly interact with divers underwater. Reef sections run from shallow areas down to around 21 metres, with visibility ranging widely from near zero up to 20 metres depending on conditions. Currents are variable, so your guide will brief you on what to expect on the day. All dives here are boat-based and run through guided tours, which is important given the sharks and surge present at this site.

This is cage diving, not scuba diving, so no dive certification is required. You descend into a submerged cage to depths of around 1 to 20 metres while great white sharks move freely around you. Visibility runs 15 to 25 metres, which means you will typically see a shark well before it reaches the cage. New Zealand fur seals and Australian sea lions are common in the area, and dolphins and sea birds are frequently spotted from the surface. The water is cold and currents can be strong, but the cage keeps you safely separated from both the sharks and the open water.

Main and Action Bays offer an exceptional introduction to South Australian diving, with conditions that suit first-time divers whilst delivering encounters that would satisfy any skill level. The bays feature varied underwater terrain including reef systems and seagrass beds, with depths ranging from shallow entry points to 30 metres in deeper waters. Visibility here reaches up to 20 metres on good days, giving you clear views of the diverse marine life that makes this area famous. You'll likely spot New Zealand fur seals and Australian sea lions, which are naturally curious and often approach divers. The bays also host bronze whaler sharks, rays, and if you're diving between May and October, you might encounter the spectacular giant cuttlefish during their breeding aggregation. Boat access means you'll start your dive from the surface without shore entry challenges. The currents vary throughout the dive, so your guide will brief you on what to expect. Whilst the marine life here is generally relaxed around divers, you're entering their territory, so maintaining respectful distances is important. The cooler months from May through October provide the best diving conditions and coincide with peak marine activity. Charter operators offer guided tours, which are particularly helpful for learning about the area's unique ecology whilst building your confidence underwater.