Meet the site
J3 was launched at Portsmouth Naval Dockyard on 4 December 1915 and commissioned into the Royal Navy in April 1916, one of the seven fast J-class boats built to work with the Grand Fleet. Six of the class came to the Royal Australian Navy in 1919 and were based at Geelong until budget cuts paid them off at Western Port in July 1922. Where J1, J2, J4 and J5 went to the Ships' Graveyard, J3 was kept closer to home: stripped of her machinery, she was scuttled in January 1926 as a pier and breakwater off Swan Point on Swan Island, then the Army's fortress and mine depot guarding The Rip, where her hull also served as a landing stage and power source for the base. She lies upright on the seabed in about 6 m with the upper deck and the base of the superstructure protruding above water, bow to the east-north-east, roughly 100 m from the island shore. Unusually, she rests on top of an earlier breakwater hulk, the 961-ton coal hulk S. F. Hersey, whose remains lie 178 m to the south-west and under her stern. J3 was the only three-screw boat of the class and the distinctive triple shaft arrangement is still visible at the stern; her two bronze propellers were removed years ago and are displayed at the Queenscliffe Maritime Museum. The pressure hull is intact for most of its length, with hatch openings and the casing gradually collapsing, and inside the bay the iron carries a coat of sponges, ascidians and small fish – leatherjackets, wrasse and seahorses in the weed. The problem is access. Swan Island is a Department of Defence facility and the waters around it, including the J3, are a prohibited area; the Scuba Doctor states plainly that the submarine is out of bounds without special permission, and charters do not visit. It is included here because it is the most complete and most visible of Victoria's J-class boats and every Queenscliff charter passes it on the way out; realistically it is a boat-viewing or museum experience rather than a dive.
What you might see
Leatherjackets, wrasse, seahorses, sponges, ascidians, sea stars, juvenile fish
Location
Scuttled as a pier and breakwater about 100 m off Swan Point on Swan Island, Queenscliff, inside Port Phillip; the upper hull breaks the surface. Lies inside the Department of Defence prohibited area.
Facilities nearby
Queenscliff Harbour: parking, toilets, cafes, boat ramp, dive shop fills.
Before you make plans
Conditions, access and operator schedules can change. This is a location guide, not a dive plan. Ask a local operator about current conditions and suitability for your training and experience.
Sources & further reading
scubadoctor.com.auscubadoctor.com.auscubadoctor.com.auen.wikipedia.orgRecord updated 26 Sept 2026. Source claims are being reviewed.