J4 26m Submarine

 Wreck Dive |  Boat access

Diesel Electric Submarine | Max Depth: 27 m (89 ft) — Graveyard

J4 in Victorian waters
© State Library Victoria

Level: Advanced Open Water and beyond.

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, plus an exciting and awe-inspiring playground for divers and freedivers.

The wreck of the J4 Submarine is located in the Victorian Ships' 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 Shipwreck

Inside the J4 Submarine
© Ian Scholey

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 Allie Beckhurst on Vimeo.

Diver Inside the J4 Submarine
© Ian Scholey

Inside the J4 Submarine can very peaceful with streams of light peering in through the cracks and holes in the hull. 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 | © Victorian Archaeological Survey

J4 Submarine Torpedo Tubes
© Ian Scholey

The broken bow section of the J4 Submarine contains four torpedo tubes, which can be easily seen by using a torch and positioning yourself between the bow and the main body.

As with the other J-class submarines, the J4 Submarine 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.

A bronze plaque has been placed on the conning tower by the Melbourne Bottom Scratchers Scuba Dive Club who rediscovered the submarine on 16 May 1982.

Inside the J4 Submarine
Looking Out at the Bow
© Ian Scholey

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.

The best part about the J4 Submarine is the relatively shallow depth. As a result, you can spend plenty of time exploring. You can easily penetrate the length of the submarine, plus spend time exploring outside.

Dive charter boats regularly schedule dives on the J4 Submarine, heading out from Portsea and Queenscliff. Private dive boats usually launch at the Sorrento Boat Ramp or the Queenscliff Boat Ramp.