Harveys Return is a small cove on Kangaroo Island's rugged north-west coast, near Cape Borda, that once served as the landing place for supplies to the Cape Borda lighthouse. Tourism Kangaroo Island recommends it for dedicated, fit snorkellers: from the campground a very steep 750 m track leads down to the water, and 'very steep so please take care' is the key advice.

Those who make the descent find a reef community with giant blue groper, harlequin fish and rainbow cale, according to both Tourism Kangaroo Island and Wander's guide. Harlequin fish, with their orange-and-blue-spotted bodies, are a prize sighting for southern Australian divers. The cove also has striking rock formations described as showing the earth's story over thousands of years. The reef is rocky and weed-covered, with sponges in shaded areas and the typical north-coast fish – wrasse, sweep, leatherjackets, magpie perch.

The logistics make scuba a serious undertaking: carrying cylinders and weights down and especially back up the steep track is exhausting, so many visitors snorkel. Northerly swells make the cove dangerous. There are no facilities at the water, and the nearest help is a long way off. For the fit and self-sufficient, though, it is one of the island's most atmospheric and least disturbed sites, and a camping stay at the top makes an early-morning dive possible. Bring plenty of drinking water, food and a first-aid kit, and allow plenty of time for the climb out; many visitors combine the snorkel with a visit to the Cape Borda lighthouse nearby.

Take the SeaLink ferry from Cape Jervis to Penneshaw (45 min), then drive west via Kingscote and the North Coast Road; the western north-coast sites are 1-1.5 hours from Kingscote on partly unsealed roads (red dirt, corrugations). Drive to the Harveys Return campground near Cape Borda (Flinders Chase area), leave the car at the campground and hike the very steep 750 m track down to the cove carrying gear – and back up afterwards. Check that the beach access track is open before visiting.

Park entry fees may apply.

Kangaroo Island's north coast faces Investigator Strait and is sheltered from the prevailing south-westerly Southern Ocean swell, so it is the island's most reliable diving coast. It is exposed to northerly and north-westerly winds and swell, which bring surge, poor visibility and dangerous entries – dive on southerly to south-easterly winds or after a few days of southerlies. Summer and autumn have the most settled weather; winter fronts bring north-westerlies before they pass.

Visibility is often 10-20 m in good conditions. Mornings are calmer before sea breezes.

Enter from the cove at the bottom of the track, follow the rocky reef along the cove edges in 3-8 m looking for groper and harlequin fish, and conserve energy for the climb back up.

No regular operator – independent snorkellers and divers only.