Petrel Cove is the small cove on the western side of Rosetta Head, best known as the starting point of the popular coastal walk to Kings Head and as a scenic lookout over the Southern Ocean. It lies on the opposite side of the headland from the Bluff jetty, where the region's most popular shore dive begins. The Bluff's granite continues around the headland, so the cove's edges are made of large boulders and granite reef with kelp and weed.

Similar habitat on the eastern side supports leafy and weedy seadragons, crayfish, seals and a variety of reef fish, and it is reasonable to expect similar life here, though without documentation. The key difference is exposure. Petrel Cove faces south-west into the swell that wraps around Kangaroo Island and Cape Jervis, and on most days waves break into the cove.

It should only be considered on rare flat-calm days after prolonged northerlies, by experienced divers who can assess the entry and have a clear exit plan. On such days, snorkelling the edges is the safer option. For most visitors, Petrel Cove is best enjoyed from the clifftop walk, with the dive at the Bluff jetty just around the corner.

Divers who do explore it are encouraged to report conditions and marine life to the Scuba Divers Federation of SA. Take care on the steps with heavy gear, and never dive the cove alone.

From Victor Harbor follow Franklin Parade/Bluff Road past the Bluff to the Petrel Cove car park on the western side of Rosetta Head (about 10 minutes from town). A short path and steps lead down to the small beach. Enter from the sand and stay close to the rocky edges of the cove.

The car park is small and fills on fine weekends when walkers use the trail, so arrive early; carry gear down in stages and leave the heaviest items until you have checked the entry.

Petrel Cove faces south-west, directly into the Southern Ocean swell, and is more exposed than the Bluff's eastern side. It is only diveable on rare flat days after sustained northerly winds with minimal swell. Waves can surge into the cove unexpectedly, and rips form when any swell is running.

Visibility can be good in calm conditions. Afternoon sea breezes usually add chop, so mornings are best.

On a flat day, enter from the beach and explore the granite boulders along the eastern (Bluff) side of the cove at 3-7 m, staying inside the cove and returning to the beach.

No operator.