Wallaroo is the main port and largest town on Yorke Peninsula, and its jetty is one of the longest in Australia and heavily used by anglers. The Marine Life Society describes the port as a modern loading terminal for wheat, and the town jetty beside it has become what local divers call a well-kept macro secret. The jetty runs a long way out over a silty bottom, reaching about 14 m at its deepest.

The Dive Shack warns that the silt requires care, as a careless fin kick can ruin visibility, and recommends entering via the swimming pool and descending between the piles while avoiding fishing lines. The Marine Life Society notes that the most colourful life is on the wharf tyres, where sponges, ascidians and small gorgonians flourish. The critter life is rich.

Nudibranchs are the headline act, occurring in high density and variety, alongside globefish, gorgonians and the usual jetty cast: seahorses, pipefish, crabs, octopus, cowfish and schools of scad and tommy ruff. Squid and cuttlefish are common, and night dives reveal decorator crabs and shrimps on the piles. Wallaroo's appeal is its combination of depth, critters and reliability as a bad-weather alternative, since the Copper Coast is sheltered from southerly swell.

Its downsides are silt, variable visibility and heavy fishing traffic. It suits Open Water divers with good buoyancy control and photographers who enjoy slow, detailed macro work. With full town services close by, it is an easy addition to a Copper Coast weekend with Port Hughes.

From Adelaide drive about 155 km (1 hour 50 minutes) via Port Wakefield and Kadina to Wallaroo. The town jetty is at the end of Jetty Road/John Terrace on the foreshore; park near the jetty head and swimming enclosure. The Dive Shack recommends entering via the swimming pool (enclosure) and descending between the piles, keeping clear of anglers' lines.

Wallaroo is the largest town on the peninsula, with full services.

The Copper Coast jetties face west into Spencer Gulf, so easterly winds – anything 'with east in it' – blow offshore and give the flattest water and best visibility, often over 10 m. Westerly and south-westerly winds blow straight onshore, raise chop and stir the fine sediment, reducing visibility to a few metres. Ocean swell barely reaches this far up the gulf, so wind is the controlling factor.

Tides are moderate; shallow sections and entry steps are easier around mid to high water. Summer afternoons bring south-westerly sea breezes, so morning dives are more reliable. Heavy rain has little effect.

The Dive Shack warns the bottom is silty – good buoyancy is essential to keep visibility.

Enter from the swimming enclosure, descend between the piles and work seaward along the jetty, checking the tyres and piles for nudibranchs and gorgonians, turning at a planned air pressure given the length. Stay neutrally buoyant off the silt and clear of fishing lines.

No resident operator; dived by Adelaide photographers and clubs as a macro site and bad-weather alternative, and by locals.