Carrickalinga Reef, below the cliffs at the northern end of Carrickalinga beach, is one of the Scuba Divers Federation's listed Fleurieu shore dives and a favourite survey site for the Marine Life Society of South Australia. A society dive report describes entering from a ramp onto the narrow beach, crossing a shallow reef and sandy bottom to deeper rocky formations with higher rocks, lots of ledges and caves and high rocky bommies, reaching 5-6 m on a 90-minute dive. Ecklonia kelp covers the rocks, and the ledges and caves shelter a good range of fish.

Society members recorded a mature male brown-spotted wrasse, silver drummer, strongfish, old wives, leatherjackets, several wrasse species and magpie perch, along with a small cuttlefish and a juvenile blue devil. A highlight was western cleaner clingfish cleaning larger fish. Another society report describes a playful bluethroat wrasse at the Carrickalinga Cliffs.

At only 5-6 m, the site allows very long dives, and its variety of habitat – shallow reef, sand, kelp, ledges and bommies – rewards slow exploration and macro photography. Visibility is often only fair, so it is more a place for close-up observation than wide vistas. Carrickalinga suits new divers, snorkellers on calm days, and naturalists who enjoy finding small behaviour.

It is a convenient stop on the way to Normanville, Second Valley or Rapid Bay, and a quieter alternative when those sites are busy. Its shallow depth also makes it a sensible choice for a second dive after a deeper morning at the Hobart or Rapid Head, and a good place to practise buoyancy over delicate kelp.

Carrickalinga is about 1 hour 10 minutes south of Adelaide, just north of Normanville. Follow the Esplanade to the northern end of the beach, park near the beach access, and walk down the ramp onto the narrow beach toward the rocks under the cliffs. Enter from the sand beside the rocks.

The walk is short, but the beach is narrow at high tide.

Carrickalinga faces west into the gulf. It is best after easterly winds with low swell; westerlies and south-westerlies make it choppy and reduce visibility. The summer sea breeze arrives in the afternoon.

Tidal flows are gentle. Visibility is often only fair, and drops after rain. Being shallow, the site is best at mid to high tide, when there is more water over the inshore reef and the entry from the narrow beach is easier; very low tides leave little depth over the first section of reef.

Enter by the rocks and cross the shallow reef, then sand, to the deeper rocky outcrops at 5-6 m. Explore ledges and bommies in a loop and return to the beach.

No regular operator; SDFSA-listed shore dive and a Marine Life Society of SA survey site.