The SS Marion is one of the oldest steamship wrecks in South Australia. Built in Glasgow in 1854, she was an iron-hulled screw steamer working the coastal passenger and cargo trade. On 10 July 1862, with 35 passengers and 15 crew aboard, she was feeling her way along the coast in fog when ocean swell lifted her onto the reef in what is now Cable Hut Bay, west of Stenhouse Bay.

All aboard reached safety, and the name Marion Bay commemorates the loss. The Department for Environment and Water describes the wreck lying in two sections on reef and a sandy bottom close to the cliffs. After more than 160 years of Southern Ocean swell, the remains are broken and scattered – iron plating, frames, machinery fragments and fittings wedged into the limestone – but enough survives to trace the two main sections, and the ironwork has been absorbed into a lively reef.

Kelp and brown algae cover the rock, sponges grow on the sheltered iron, and sweep, old wives, magpie perch, zebrafish and blue groper move through the wreckage, with crayfish under plates. The site is on the Investigator Strait Shipwreck Trail but is rarely dived because it requires a boat and calm weather, and it lies close to the cliffs where surge builds quickly. For divers working through the trail it is an evocative dive in a dramatic setting, and it combines well with Chinamans Hat or the Stenhouse Bay jetty and Hougomont.

It suits Open Water divers with some experience of surge. Depths are moderate and navigation straightforward on a calm day. The wreck is protected – look, photograph, and leave everything in place.

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 run west past Stenhouse Bay to Cable Hut Bay (about 15-20 minutes). The wreck lies close to the cliffs on reef and sand; use the DEW trail coordinates.

Cable Hut Bay can be viewed from the park road but shore access down the cliffs is not practical for divers.

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. Cable Hut Bay is exposed to southerly swell, which lifted the Marion onto the reef in 1862; surge over the shallow reef is the main limitation.

Anchor on sand off the reef, locate the larger of the two sections and explore the iron plating and machinery, then follow scattered debris across the reef to the second section. Keep clear of the surge zone near the cliffs.

No regular operator; dived by private boats and Adelaide clubs exploring the Investigator Strait Shipwreck Trail.