Alert was an iron screw steamer of 243 tons built by Robert Duncan at Port Glasgow in 1877, 51.5 m (169 ft) long, which arrived in Melbourne on 30 May 1878 and spent sixteen years as a bay and coastal trader between Melbourne, Portarlington and Geelong and later along the Gippsland coast. On 28 December 1893 she left the Gippsland Lakes trade at Bairnsdale with 44 tons of cargo under Captain Albert Mathieson, bound for Melbourne. Off Cape Schanck she met a south-westerly gale; seas drove in the stokehold covers and a pantry door, water reached the boiler fires and put them out, and with no steam she fell broadside to the sea and sank stern first at about 4.30 pm.

Fifteen of the sixteen aboard died. The cook, Robert Ponting, clung to a cabin door for sixteen hours and was washed ashore unconscious, the sole survivor. The wreck was lost for 114 years until Southern Ocean Exploration, the Melbourne technical diving team, located her on 27 June 2007 about 10 km south of Cape Schanck in 75 m.

What they found was extraordinary: the iron hull sitting upright and largely intact, all the below-deck spaces still enclosed, a lifeboat davit bent against the hull by the seas that sank her, portholes in place and bottles and plates lying where they fell. Because it is a grave, and because artefacts began to disappear, the site was declared a historic shipwreck protected zone with a 500 m radius under the Underwater Cultural Heritage Act 2018; a Heritage Victoria permit is required to dive and anchoring is banned. Alert is not a dive that can be booked.

It is a 75 m expedition dive for closed-circuit rebreather teams with permits, support boats and the patience to wait for the two or three days a year when Bass Strait allows an hour of decompression off Cape Schanck. For Victorian technical diving it is a landmark – one of the most significant intact nineteenth-century wrecks in Australian waters, and a reminder that the deep Bass Strait wrecks are protected for good reason.

Boat only, and only with a Heritage Victoria permit. Technical expeditions have run from Flinders (Western Port) and from Queenscliff/Portsea; Flinders boat ramp at the end of the pier road is the closest launch, about 15 km east-north-east of the site, giving a 30–40 minute run around Cape Schanck in a fast boat, while Queenscliff is roughly 35 km and over an hour. Drive Melbourne–Flinders via the Mornington Peninsula Freeway and Boneo Road (about 1 h 30 min).

Anchoring is prohibited within the protected zone; the shot must be placed clear of the hull and the surface vessel remains live-boating throughout the long decompression.

Completely exposed to the Southern Ocean off Cape Schanck – the same gale that sank her. Any south-west or westerly swell over about 1 m makes a 90-minute decompression hang unsafe, and strong tidal and wind-driven currents run across the site; the Scuba Doctor describes conditions as difficult, with exposed seas, poor visibility and strong currents, and calm conditions as essential. Windows are rare – perhaps a few days a year when a high sits over Bass Strait with light northerlies and no residual swell.

Visibility is often reduced by suspended silt and plankton at 75 m. Expeditions plan for slack water and a dawn start.

Expedition CCR dive. Descend the shot to the seabed beside the hull (75 m), spend about 20 minutes surveying the upright iron hull from the davit and stern to the bow – no entry, no touching – then return to the shot and ascend with roughly an hour of staged decompression on a trapeze under the live boat, with surface support and in-water safety divers at the shallow stops.

Expedition-grade CCR dive: hypoxic trimix diluent (e.g. 10/60–12/65), full bailout for a 75 m ascent, oxygen and EAN50 stages or in-water support, decompression trapeze under a live boat. Heritage Victoria permit mandatory; no anchoring within 500 m of the wreck.

No commercial operator. Dived by Southern Ocean Exploration (the technical team that found her in 2007) and occasional permitted expeditions by Melbourne technical rebreather divers, a handful of times since discovery. A Heritage Victoria permit is required for every dive.