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J4 26m Submarine

Wreck DiveWreck Dive | Boat access

Advanced Open Water Rated Outside Port Phillip Wreck Dive Site

Diesel Electric Submarine | Max Depth: 27 metres (89 feet) — Graveyard

J4 Submarine in Victorian waters
J4 in Victorian waters
© Allan Green, State Library of Victoria

The J4 Submarine (aka Shallow, 26 metre, 27 metre and 90 Foot Broken sub) is part of our very own piece of WWI maritime history and an exciting and awe inspiring playground for divers and freedivers.

The wreck of the J4 Submarine is located in the ship graveyard, Bass Strait. It lies on its keel running North-South with its bow pointing out to sea on a rocky seabed.

Scuba Diving and Freediving the J4 Submarine

J4 Submarine conning tower, Victoria, Australia
J4 Submarine conning tower
© Mary Malloy & Alan Beckhurst

The stern of the J4 submarine almost merges into the surrounding reef. (See also Sub Reef.) During its scuttling the bow section broke off, exposing the forward torpedoes tubes and bow modifications. This makes the torpedo tubes easily accessible to scuba divers without penetration. The conning tower is intact and in excellent condition.

Scuba divers and freedivers can penetrate the submarine through the numerous hatch openings. Such penetration should not be taken lightly, as being shallower than the other subs, this wreck is particularly susceptible to surge. Unwary divers can be literally sucked in and catapulted through the wreck's interior. However, the surge prevents any silting, and under suitable conditions this makes for one of Melbourne's top dives.


J4 Submarine Wreck from Alan Beckhurst on Vimeo.

Once inside, divers can see the bulkheads, which supported the submarine against pressure at great depths. Although the engine has been removed, the engine bed can still be seen at the stern.

J4 Submarine dive site plan
J4 Submarine dive site plan
© Victorian Archaeological Survey

The broken bow section of the submarine contains four torpedo tubes, which can be easily seen by using a torch and positioning yourself between the bow and the main body.

A bronze plaque has been placed on the conning tower by the Melbourne Bottom Scratches Dive Club who rediscovered the submarine in 1982.

As with the other Subs, the J4 sub is host to a variety of plant and animal life. Good conditions for photography are often found near the conning tower, which is usually surrounded by many fish.

The J4 submarine is an excellent dive for Advanced Open Water divers. As this is a penetration dive, divers should be experienced, plus appropriately qualified and equipped. Some experienced freedivers have been known to descend down and through the J4 submarine.

J4 Submarine History

J4 moored in Sydney following the voyage to Australia
J4 moored in Sydney following
the voyage to Australia
© Royal Australian Navy

Originally HMS J4, later HMAS J4, this is one of the J class submarines designed and built during WW1 by the British Royal Navy. HMS J4 was commissioned in the Royal Navy on 17 July 1916. The wartime complement was 5 officers and 40 sailors.

At the completion of the first World War in 1919, the British Government gave Australia a gift of the remaining six J class submarines, plus six navy destroyers. All the submarines were commissioned into the Royal Australian Navy at Portsmouth on 25 March 1919.

J1, J4, J2 alongside HMAS Platypus, circa 1920 
title=
J1, J4, J2 alongside HMAS Platypus,
circa 1920
© Royal Australian Navy

Having arrived in Sydney, Australia on 15 July 1919 in poor condition, the J-class submarines were taken in hand at Garden Island Dockyard for refitting. After her refit was completed J4, in company with J1 and HMAS Platypus, sailed on 16 February 1920 for the submarine base at Geelong, Victoria.

After uneventful service in Australia, little of which was spent at sea, J4 and her five sisters were paid off into Reserve at Westernport on 12 July 1922. The boats had become victims of the worsening economic conditions of the time, coupled with their high cost of maintenance.

On 26 February 1924 J4 was sold to the Melbourne Salvage Syndicate. On 10 July 1924 she sank at Williamstown Dockyard wharf but was later raised and scuttled by explosives on 28 April 1927 outside Port Phillip Heads.

J4 Submarine Details

J4 general arrangement plan as originally fitted.
J4 general arrangement
plan as originally fitted.
© Royal Australian Navy

Built in 1915/1916 at Portsmouth Naval Dockyard, England, launched on 2 February 1916 as a double hulled type, triple screw submarine. The overall length of the vessel was approximately 83.7 metres (275 feet), beam 7.2 metres (24 feet) and draught 4.3 metres (14 feet) giving a displacement weight of 1,092 tonne (1,204 short tons) surfaced.

Top speed was 19 knots (35 km/h; 22 mph) on the surface, and 9.5 knots (17.6 km/h; 10.9 mph) underwater. Range was 4,000 nautical miles (7,400 km; 4,600 mi) at 12 knots (22 km/h; 14 mph). Propulsion was via three 12 cylinder Vickers, solid injection, direct reversing, 4 cycle diesel engines, 1200 HP at 380 RPM, while surfaced. Two Mather and Platt, 1400 HP electric motors powered by four banks of 58 cell batteries, when submerged.

The J4 submarine was armed with one 4-inch deck gun, plus six 18 inch (450 mm) torpedo tubes — four forward, and one on each beam. She was also fitted with an arrangement for discharging depth charges or mines.

For more information see the J4 Submarine page on the Heritage Victoria web site, or download/view the J4 Submarine Dive Information Sheet (Adobe PDF | 564.76 KB).

Four subs, J1, J2, J4, and J5, were scuttled in the ship graveyard. Two were scuttled as breakwaters: J3 near Swan Island, and J7 at Sandringham Yacht Club.

See also Wikipedia: HMS J4,
Australian National Shipwreck Database: J-4 Submarine,
Heritage Council Victoria: J-4 Submarine, and
Royal Australian Navy: HMAS J4.

Findling the J4 Submarine

Over the years we've been provided with different GPS marks for the J4 Submarine. The GPS marks we know of in circulation for the J4 Submarine are:

  • Victoria's Ships' Graveyard:
    Latitude: 38° 17.979′ S   (38.299657° S / 38° 17′ 58.77″ S)
    Longitude: 144° 33.820′ E   (144.563673° E / 144° 33′ 49.22″ E)
  • Dive Victoria:
    Latitude: 38° 17.968′ S   (38.29946667° S / 38° 17′ 58.08″ S)
    Longitude: 144° 33.829′ E   (144.56381667° E / 144° 33′ 49.74″ E)
  • Alan Beckhurst:
    Latitude: 38° 17.986′ S   (38.29976667° S / 38° 17′ 59.16″ S)
    Longitude: 144° 33.813′ E   (144.56355° E / 144° 33′ 48.78″ E)

Latitude: 38° 17.979′ S   (38.299657° S / 38° 17′ 58.77″ S)
Longitude: 144° 33.820′ E   (144.563673° E / 144° 33′ 49.22″ E)

Datum: WGS84 | Google Map
Added: 2012-07-22 01:00:00 GMT, Last updated: 2019-05-09 01:49:08 GMT
Source: Book - Victoria's Ships' Graveyard GPS (verified)
Nearest Neighbour: Sub Reef, 440 m, bearing 95°, E
J-Class Submarine, 1820 ton.
Built: Portsmouth, UK, 1915/1916.
Scuttled: 28 April 1927.
Depth: 19 to 28 m.



DISCLAIMER: No claim is made by The Scuba Doctor as to the accuracy of the dive site coordinates listed here. Should anyone decide to use these GPS marks to locate and dive on a site, they do so entirely at their own risk. Always verify against other sources.

The marks come from numerous sources including commercial operators, independent dive clubs, reference works, and active divers. Some are known to be accurate, while others may not be. Some GPS marks may even have come from maps using the AGD66 datum, and thus may need be converted to the WGS84 datum. To distinguish between the possible accuracy of the dive site marks, we've tried to give each mark a source of GPS, Google Earth, or unknown.

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