Pioneer was a steel steam suction (pump) dredge of 543 tons built in 1905 by Ferguson Brothers at Port Glasgow for the Melbourne Harbour Trust. She was 51.8 m (170 ft) long with a 37 ft beam and sailed out under her own steam, arriving in Port Phillip on Friday 4 August 1905 after an 84-day voyage. For 45 years she kept the Yarra and the bay channels clear of sand, one of the workhorses that made the modern port possible, until she was replaced and scuttled in the Graveyard on 9 March 1950; some of her equipment went into a successor, Pioneer II.

She is one of the most complete large wrecks off Victoria. The hull sits in 46–50 m with the superstructure top around 42 m; both propellers are still in place at the stern, the pump and dredging machinery is recognisable, and the hull sides stand high enough to give the feel of swimming along a ship rather than over a debris field. Penetration is limited but possible along the sides, at the stern and at the bow, and a torch reveals machinery spaces still full of fittings.

Growth is heavy – sponges, zoanthids and ascidians on every horizontal surface – and the wreck attracts ling, boarfish, bullseyes and big crayfish. Visibility is typically 10–20 m in autumn and winter after a settled spell. Like the Euro a kilometre to the south, the Pioneer is a normoxic-trimix dive that rewards a second and third visit.

It suits technical divers who like machinery and a hull with height, and it is often combined with the Euro or the H.C. Piggot on a technical charter. Together with the Batman group it forms the core of what Melbourne technical divers call the 'western Graveyard' circuit.

Boat only. The western end of the Ships' Graveyard sits 8–12 km south of Barwon Heads and is normally reached from Queenscliff Harbour (Red Boats, Dive Victoria Group technical charters) – a 40–60 minute run out through The Rip and west along the Bellarine coast – or occasionally from the Barwon Heads river ramp in a small boat when the bar is flat. Drive Melbourne–Queenscliff via the Geelong Ring Road and Bellarine Highway (about 1 h 40 min).

Technical charters usually load at the harbour before dawn to get the wreck dived before the afternoon sea breeze. Private boats need a reliable sounder and the published GPS marks, as nothing shows on the surface.

Fully exposed Bass Strait. South-westerly swell is the killer: most charters will not run on a forecast over about 1.5 m, and anything from the south or west over 2 m makes the site undiveable and the passage through The Rip dangerous. Northerly and north-easterly winds flatten the sea; a calm morning after several settled days gives the best visibility (often 15–25 m in autumn and winter).

Surge is felt on the wreck in any swell over 1 m. Tidal streams outside The Heads are weaker than inside but still run; charters aim for slack water at Port Phillip Heads or a favourable tide for the transit. Winter westerlies close the site for weeks at a time.

The wreck sits in or near the shipping approach and pilot boarding ground, so a shot line, surface cover and a delayed SMB are mandatory.

Shot onto the superstructure. Start at the stern to see both propellers, work forward along one side of the 52 m hull past the pump machinery and dredge gear, round the bow and back along the other side; short penetrations along the sides, stern and bow for trained divers. Ascend the shot at 20 minutes with 25–35 minutes of decompression.

Technical (decompression) dive. Normoxic trimix (e.g. 21/35 or 18/45) recommended; 20 min bottom time gives roughly 25–40 min of decompression on EAN50 and oxygen. Air dives to this depth are strongly discouraged.

Drop a weighted shot on the wreck, use a delayed SMB from the wreck or a decompression trapeze under the boat; the site is in a shipping approach so free-drifting deco is discouraged.

Red Boats (Queenscliff) and Dive Victoria Group technical charters a few times a season; private technical boats. One of the more popular western Graveyard wrecks because of its completeness.