HMAS J1 Submarine

HMAS J-Class Submarines, Bass Strait

By ScubaDownUnder Team · 2026-09-11

Outside Port Phillip Heads, in the stretch of Bass Strait known as the Victorian Ships' Graveyard, four First World War submarines lie on the seabed: the J1, J2, J4 and J5. They sit between about 19 and 39 metres, and divers have been exploring them since the 1970s. They are rewarding wrecks, with torpedo tubes, conning towers and hulls you can swim through, but they are also deep, cold and sometimes dark, and they have claimed divers' lives. Treat them as dives for trained, well-equipped divers.

## A Short History

The J class was built for the Royal Navy in 1915 to 1917, after rumours that Germany had submarines fast enough to work alongside a battle fleet. The rumours were false, but the British boats that resulted were the only submarines ever built with three propeller shafts, and with a surface speed of about 19 knots they were the fastest submarines of their day. In November 1916 the J1 torpedoed and damaged the German battleships Grosser Kurfürst and Kronprinz in the North Sea.

After the war the Admiralty presented the six surviving boats to Australia (the J6 had been sunk in error by a British ship in 1918). They commissioned into the Royal Australian Navy at Portsmouth in March 1919, sailed for Australia in April and were based at Geelong, but they spent little time at sea and were paid off into reserve at Westernport on 12 July 1922. In 1924 the J1, J2, J4 and J5 were sold to a Melbourne salvage firm.

The hulls of the J1, J2 and J5 were sunk about three miles off Barwon Heads in 1926: the J1 on 26 May, the J2 on 1 June and the J5 on 4 June. The J4 took longer. She sank at her berth at Williamstown on 10 July 1924 while she was being stripped, was raised in December 1926, and on 28 April 1927 was towed about four miles outside Port Phillip Heads and scuttled. The other two boats became breakwaters: the J3 at Swan Island in 1926 and the J7 at Sandringham in 1930.

Divers found the wrecks again decades later. The Geelong Skindivers Club located the J2 in February 1974 and the J5 in May 1974, the Melbourne Bottom Scratchers relocated the J4 in May 1982, and the J1 was rediscovered in October 1984.

## The Four Wrecks

The [J4](https://scubadownunder.com/dive-sites/hmas-j4-submarine) is the shallowest, in about 19 to 28 metres, and a favourite with Melbourne wreck divers. She lies on her keel on a rocky bottom, her stern almost merging into the reef. The bow broke off when she was scuttled, exposing the four forward torpedo tubes, which you can see without entering the hull, often with schools of bullseyes around them. The conning tower is intact. Lloyd Borrett rates the J4 a dive for Advanced Open Water divers, but warns that surge pumping through the hatches can suck unwary divers in and throw them through the hull.

The [J5](https://scubadownunder.com/dive-sites/hmas-j5-submarine), known as the Yellow Submarine, sits upright on sand in about 36 metres, with her conning tower rising to about 30 metres (Divernet gives the depth as 40 metres). Yellow zoanthids cover the bow, stern and conning tower, along with sponges and ascidians, and bullseyes, longfin pike, barber perch and splendid perch gather around the conning tower. Large openings in the deck make penetration easy, but the bow silts up. A severe storm in 1994 stripped plating and zoanthids from the hull, and the wreck has kept deteriorating since.

The [J1](https://scubadownunder.com/dive-sites/hmas-j1-submarine), nicknamed the New Deep Sub, lies almost upright in about 31 to 38 metres. She is covered in yellow zoanthids, with plenty of fish around the top. The 1994 storm lifted the J1 off the bottom and cracked her hull behind the conning tower, and divers now describe her as the most broken of the four. Penetration is possible, but tight doorways and silt make it hazardous, and divers have died here.

The [J2](https://scubadownunder.com/dive-sites/hmas-j2-submarine), the Broken Sub, lies in about 31 to 39 metres. Explosive charges broke her in two near the conning tower when she was scuttled, and the front half lists to starboard. The break gives access to the interior but is lined with jagged, twisted metal. Divers report a large wobbegong and blue devilfish living on the wreck, and crayfish that can be heard inside. The J2 is the closest of the four to the Heads and to the shipping channel, and the least dived. A diver went missing on the J2 in 1981, and another died on a penetration dive in January 1997.

## Conditions and Safety

Lloyd Borrett's logged dives on these wrecks recorded water of 13°C in June and November and up to 19°C in January, so a drysuit is the sensible choice. Visibility varies a great deal: Borrett had 7 to 10 metres on a good day on the J2, while on the day of the 1997 fatality it was 2.5 to 4 metres near the surface and only 1 to 2 metres beside the wreck. Surge can be felt even at depth, and the openings in the hulls funnel currents.

Divernet's guide puts typical run times at about 55 minutes and says divers should be wreck and deep certified, carrying good lights and guidelines, with twin cylinders or a rebreather for penetration. Borrett warns that decompression stops are inevitable on the J2, and two of his four dives on the J5 needed them, so plan gas carefully and be ready to hang on a line.

## Heritage Protection

All four wrecks are more than 75 years old, so the Underwater Cultural Heritage Act 2018 protects them automatically; it replaced the Historic Shipwrecks Act 1976 in 2019. You are free to dive them, but you must not disturb or damage the wrecks or remove anything, and any new discovery must be reported. None of the J-class submarines sits in a declared protected zone, so no permit is needed to visit.

## Site Access and Logistics

The submarines are boat dives only. Charter boats schedule them from Portsea and Queenscliff, and private boats usually launch at the Sorrento or Queenscliff ramps. The J2 lies about three kilometres south of Point Lonsdale. The Scuba Doctor publishes these GPS marks (WGS84) from the book Victoria's Ships' Graveyard, listed as GPS verified: J1 -38.315988, 144.553648; J2 -38.313570, 144.580048; J4 -38.299657, 144.563673; J5 -38.310822, 144.568632.

The J1 and J2 sit close to the shipping route into Port Phillip, so boat crews need to keep watch for traffic. The J4 suits experienced Advanced Open Water divers; the J1, J2 and J5 call for deep training and decompression planning, and The Scuba Doctor lists Deep 40 metre certification for the J1. Going inside any of the hulls is an overhead dive that needs wreck training and equipment.

## Sources

- [Sea Power Centre Australia: HMAS J1](https://seapower.navy.gov.au/history/units/hmas-j1) - [Sea Power Centre Australia: HMAS J2](https://seapower.navy.gov.au/history/units/hmas-j2) - [Sea Power Centre Australia: HMAS J3](https://seapower.navy.gov.au/history/units/hmas-j3) - [Sea Power Centre Australia: HMAS J4](https://seapower.navy.gov.au/history/units/hmas-j4) - [Sea Power Centre Australia: HMAS J5](https://seapower.navy.gov.au/history/units/hmas-j5) - [Sea Power Centre Australia: HMAS J7](https://seapower.navy.gov.au/history/units/hmas-j7) - [Lloyd Borrett: Dive Site, J2 Submarine](https://www.borrett.id.au/divelog/divesite.php?id=33) - [Lloyd Borrett: Dive Site, J4 Submarine](https://www.borrett.id.au/divelog/divesite.php?id=30) - [Lloyd Borrett: Dive Site, J5 Submarine](https://www.borrett.id.au/divelog/divesite.php?id=99) - [Lloyd Borrett: Lessons To Be Learnt (J2 dive and 1997 fatality, PDF)](https://www.borrett.id.au/downloads/dive_article_lessons_to_be_learnt.pdf) - [Lloyd Borrett: Dive log 142, J4 Submarine, November 2007](https://www.borrett.id.au/divelog/index.php?id=142) - [Lloyd Borrett: Dive log 230, J5 Submarine, January 2010](https://www.borrett.id.au/divelog/index.php?id=230) - [Lloyd Borrett: Dive log 276, J5 Submarine, June 2010](https://www.borrett.id.au/divelog/index.php?id=276) - [Divernet: Discover the Hidden Treasures of Victoria's J-Class Submarines](https://divernet.com/scuba-diving/discover-the-hidden-treasures-of-victorias-j-class-submarines/) - The Scuba Doctor: J Class Submarine Wreck Dives, and J1 Deep Submarine (scubadoctor.com.au; the site blocks automated link checks) - [Australasian Underwater Cultural Heritage Database: J-1 Submarine](https://www.environment.gov.au/shipwreck/public/wreck/wreck.do?key=6296) - [Victorian Heritage Database: J-1 Submarine](https://vhd.heritagecouncil.vic.gov.au/shipwrecks/356) - [DCCEEW: Underwater Cultural Heritage Act 2018](https://www.dcceew.gov.au/parks-heritage/heritage/underwater-heritage/underwater-cultural-heritage-act) - [DCCEEW: Visiting underwater heritage sites](https://www.dcceew.gov.au/parks-heritage/heritage/underwater-heritage/visiting-underwater-heritage-sites) - [DCCEEW: Underwater heritage protected zones](https://www.dcceew.gov.au/parks-heritage/heritage/underwater-heritage/protected-zones)

Header photo: Point Lonsdale Lighthouse on the western side of Port Phillip Heads, the headland north of the J-class wrecks, by Bernard Spragg, [CC0, via Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Point_Lonsdale_Lighthouse,_Vic_Aust._%2819164571983%29.jpg).