Tank Cave is a submerged freshwater cave system in South Australia that demands full cave diving certification and a serious respect for overhead environments. Depths run from 15 to 20 metres, with visibility ranging from 10 to 30 metres depending on conditions within the system. There is no current to manage, but the hazard list is substantial: narcosis, entanglement risk, decompression considerations, and the ever-present reality of diving beyond daylight. The draws are genuinely unusual: stygofauna adapted to perpetual darkness, and fossils embedded in the cave structure. This is a site for divers who treat penetration diving as a discipline, not an adventure.

Fossils Cave is a cave dive offering something genuinely rare: embedded fossils of extinct megafauna visible in the cave walls and substrate. Visibility holds at 40 metres in crystal clear water, and depths run 13 to 15 metres, but the overhead environment demands full cave training and appropriate redundancy before you consider entry. There is no current to contend with, but entanglement risks and the requirement for decompression planning mean this is strictly expert territory. The site also shelters rare crustaceans of the genus Koonunga, a find that few divers ever encounter. Cold water throughout the year calls for a well-fitted drysuit.

Kilsby Sinkhole is a freshwater blue hole on private property in South Australia, and its visibility is genuinely remarkable at 50 to 80 metres. The water is exceptionally clear and cold, dropping to 60 metres in deep diving territory, with a cavern environment that creates dramatic light effects near the surface. Current is non-existent, so conditions are calm and controlled. The resident turtle, Turtie, is a well-known presence here and a reliable highlight for visiting divers. Because this is an overhead environment, proper cavern or cave diving awareness is important before descending beyond the natural light zone.

The Little Blue Lake is a freshwater blue hole and cavern dive in South Australia, reaching depths of 25 to 47 metres. Visibility here is genuinely variable and can shift dramatically depending on conditions, so come prepared for anything from clear water to near-zero viz. There is no current, but the overhead environment, cold water, and depth push this firmly into serious intermediate territory. The resident freshwater eels are the main wildlife encounter in this unusual inland setting. Proper overhead environment training and a torch are essential, not optional.

Port MacDonald Pier is a shore dive in South Australia that rewards slow, patient exploration. The pier pylons act as an artificial reef, hosting a surprisingly dense community of bryozoans, hydroids, soft coral, and gorgonian coral growing directly on the structure. Weedy sea dragons are a genuine highlight here, drifting close to the pylons where they blend into the growth. Crayfish and feather stars round out the marine life. The water is shallow and calm with no current, making it approachable for beginners, though visibility can vary and the water is cold, so a good wetsuit is essential. Watch your movements around the structure to avoid entanglement.

Ewens Ponds is a freshwater spring system, which makes it unlike almost any other dive site in Australia. Three interconnected ponds feed into each other via a gentle drift current, carrying you through visibility that reaches 50 to 80 metres. At depths of just 1 to 10 metres, it is perfectly suited to beginners. Keep your eyes on the thick aquatic plant growth lining the banks, where freshwater crayfish, eels, galaxias, and the tiny Ewens pygmy perch all live. Turtles also pass through. The cavern sections require awareness of the overhead environment, so stay close to the guide rope and never exceed your training.

Piccaninnie Ponds is a freshwater cave system in South Australia where visibility can stretch to 60 metres, making the geometry of the underwater environment unnervingly clear. The main pond connects to The Chasm, a vertical fissure that drops into deep diving territory at 35 metres, and navigation demands solid buoyancy control and overhead environment experience. Cold water is a constant, so a drysuit or thick wetsuit is non-negotiable. The resident fauna is understated but genuinely unusual: freshwater eels, Common Galaxias, Congolli, Southern Pygmy Perch, and aquatic plants that thrive in the low-nutrient, gin-clear water. Current is mild and rarely a concern.

Cape Buffon at Southend is a shore dive off a reef system in shallow, calm waters, making it a solid choice for intermediate divers wanting to explore a temperate South Australian site. Visibility is variable, so conditions can shift between visits. Current is also variable, so check before you enter. The reef holds a good mix of marine life including mulloway, salmon, sharks, rays, abalone, crayfish, sea stars, and sponges. Watch for sharp coral on entry and exit, and keep an eye on the surf. Spring through early autumn offers the most reliable window for diving here.