The City of Rayville was a 5,883-ton American steel freighter built in 1920 at Tampa, Florida, for the United States Shipping Board and operated in 1940 by the Pioneer Line. On the evening of 8 November 1940, bound from Adelaide to Melbourne with a cargo of lead, she struck a mine laid across the western entrance to Bass Strait by the German auxiliary minelayer Passat, working with the raider Pinguin. The explosion blew off the foremast and opened the forward holds; the ship sank in about 40 minutes some 6 miles south of Cape Otway. Thirty-seven of the 38 crew got away in the boats and were brought into Apollo Bay by local fishermen; the third engineer, who went back for belongings, drowned. The same minefield had sunk the British steamer Cambridge off Wilsons Promontory the day before. The City of Rayville has a place in history as the first American merchant ship lost in the Second World War, more than a year before the United States entered it, and a memorial stands on the Apollo Bay foreshore.

The wreck was located by sonar in the early 2000s and lies upright on sand in about 82 m, with the hull and superstructure standing 5–6 m clear of the seabed. Survey imagery shows the steering house, hatch coamings, ladders, railings and deck winches still in place, and the hull largely intact apart from the mine damage forward. It sits within the Commonwealth Apollo Marine Park and is protected under the Underwater Cultural Heritage Act. For divers this is one of the deepest and least visited wrecks in Victoria: a trimix or rebreather dive with a long run offshore, cold water, poor weather odds and no regular charter, undertaken only by well-equipped technical teams. It is included here as the outstanding deep wreck of the Otway coast rather than as a practical dive for most readers.

Technical boat dive only. Charter or private technical boats launch from Apollo Bay harbour (Breakwater Road ramp) and run about 25 km south-west to the position, 60–90 minutes in a fast boat depending on sea state; Port Campbell's crane launch is the only alternative to the west and is unsuitable for larger vessels. The Australian National Shipwreck Database position is regarded as unreliable and the wreck must be relocated by sounder.

Expeditions are organised by Melbourne technical dive groups and are weather-dependent for days at a time.

Fully exposed to the Southern Ocean off the most notorious cape in Victoria. Requires swell under about 1 m and winds under 10 knots for a full day, which happens on only a few days a year, usually in late summer and autumn under a slow-moving high. Surface currents and a west-setting drift are common and a live-boat pick-up with a drifting deco station is standard practice.

Fog and rapid frontal changes are hazards. Water at depth is cold year-round (11–14 °C) and the Bonney Upwelling can bring cold, green water inshore in summer. Slack water is not the constraint; sea state and the long run home are.

Descend the shot to the deck at about 75 m, confirm the shot is secure, then work along one side of the hull past the hatch coamings, winches and steering house on the stern, keeping the run-time tight. Bottom time of 20–25 minutes on trimix gives a total run time of well over two hours; ascend the shot or a deployed deco station and complete staged decompression with team bailout and surface support.

Trimix (e.g. 12/60) or CCR with bailout; typical plan 20–25 min bottom time, 120–150 min run time; deco on 50% and O2; drifting deco station and live-boat recovery recommended; surface support with O2 and satellite communication essential. Protected under the Underwater Cultural Heritage Act 2018 – no disturbance.

No regular operator. Rare expeditions by Melbourne-based technical dive groups (trimix/rebreather) using chartered or private vessels from Apollo Bay; the wreck has been dived only a handful of times since it was located.