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Victoria · Wreck

J3 Submarine (Swan Island)

The most complete J-class submarine in Victoria, upright with its deck above water 100 m off Swan Island and resting on the hulk S. F. Hersey – but inside a Defence prohibited area and effectively off-limits.

Melbourne & Port Phillip BayBoat
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YouDive mascot illustration; not a photograph or site map

Mascot illustration — not a photograph or site map.

Depth
0–8 m
Certification
Open Water
Access
Boat
Dive type
Wreck
Region
Melbourne & Port Phillip Bay

Depth describes the recorded site range, not a recommended dive depth. Certification is a recorded recommendation; suitability depends on your planned route, training, experience and current conditions.

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Location & map

Recorded location

Interactive map provided by Google Maps. If the map does not load, use the larger-map link.

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.

Research this site before booking

J3 Submarine (Swan Island) is recorded as Wreck in Melbourne & Port Phillip Bay. The listed access is boat. Confirm the actual meeting point, route and permission to visit; a map pin does not establish any of these.

Topics flagged by the stored research

These are questions prompted by the existing notes, not a verified or complete hazard assessment.

Current and timing
Ask how the operator assesses the current window for the actual route. Historical tide notes are not a departure instruction.
Other water users
Ask about vessel activity, exclusion areas and the agreed surface arrangements.

Historical access notes exist for this record, but have not been independently verified for current use. Request current directions from the operator or site manager rather than following an old entry description.

Questions, answered

Is J3 Submarine (Swan Island) suitable for my certification?

The record lists Open Water. That does not establish suitability for every route or day. Share your training, recent experience and equipment needs with the operator and ask about the specific proposed dive.

Can I book J3 Submarine (Swan Island) through YouDive?

YouDive is an independent research directory. Contact an operator directly to confirm whether it currently runs the trip, the inclusions and the booking terms.

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.

Record updated 26 Sept 2026. Source claims are being reviewed.

More records in this region

Grouped by directory region, not distance or equivalent difficulty.

Operators linked to this site

These links are recorded in the directory. Confirm current trips and site access directly.