The Pareora was a steel-hulled screw steamer built in 1896 at Newcastle-upon-Tyne, England. On 18 September 1919, carrying 672 tonnes of zinc concentrate from Port Pirie, she was caught in heavy seas and struck rocks on the northern side of Althorpe Island. Eleven of her 18 crew drowned, including the captain – one of the worst losses of life on this coast.

The Department for Environment and Water records the wreck lying in a gully between reefs on the northern side of the island. More than a century of swell has broken her up, but substantial pieces remain: the boiler, engine, an anchor and windlass and sections of plating are wedged into the gully, overgrown with kelp, sponges and encrusting life. Fish use the wreckage as shelter – blue groper, sweep, old wives, magpie perch and bullseyes – and seals from the island colonies often investigate divers.

The Pareora is one of two located wrecks at Althorpe on the Investigator Strait Shipwreck Trail, the other being the fishing vessel Mylor Star on the south-west corner. Several other vessels lost around the island – the Young St George, Welling, Rapid and Altair – have not been found, and divers who come across unidentified wreckage are asked to report it to Heritage SA. Because of the open-water crossing, exposure and strong currents, this is an expedition-style dive for experienced divers with a capable boat.

It is best combined with wall and seal dives around Althorpe on the same trip, making the long crossing from Marion Bay worthwhile. Take photographs only and leave all fittings where they lie.

From Adelaide drive about 300 km (3.5 hours) via Port Wakefield, Minlaton and Warooka to Marion Bay; Dhilba Guuranda-Innes National Park begins just west of the township (vehicle entry fee, pay online or at the Stenhouse Bay visitor centre). Launch at Marion Bay and cross about 20 km south-west past Cape Spencer to the northern side of Althorpe Island (40-50 minutes). Use the DEW coordinates; the wreck lies in a gully between reefs.

The crossing is open water – only go in settled weather with a seaworthy boat.

The southern tip of Yorke Peninsula faces the open Southern Ocean and Investigator Strait, so south-westerly and southerly swell is the controlling factor: most exposed sites need swell under about 1.5 m and are best after several days of northerly or north-easterly winds, which blow offshore along this coast. Winter cold fronts bring big south-westerly swell and strong winds and can close the area for days. Summer afternoon south-easterly sea breezes make boat runs rough, so launch early.

Visibility is typically 10-20 m in settled conditions but drops sharply with swell-driven surge. The northern side of Althorpe offers some shelter from southerly swell, but currents around the island are strong and the gully can surge.

Anchor off the reef, descend into the gully and follow the wreckage – boiler, engine, anchor and windlass – along the gully floor, then exit over the reef to the boat. Carry an SMB.

No regular operator; dived by private boats and club expeditions to Althorpe Island.