HMS J1 (later HMAS J1) was a J-class submarine operated by the Royal Navy and the Royal Australian Navy.
Design and construction
The J class was designed by the Royal Navy in response to reported German submarines with surface speeds over . They had a displacement of 1,210 tons surfaced, and 1,820 tons submerged.
Service history
J1 operated in patrols in the North Sea. In November 1916, a German force of half a destroyer flotilla, three dreadnoughts, and a battlecruiser set out from port to rescue two submarines and that were stranded in fog off Jutland. On the return, having only rescued one of the submarines, the force passed J1 off Horns Reef on 5 November 1916. Two of the dreadnoughts, and , were torpedoed by J1, earning her commanding officer, Commander N. F. Laurence, a Bar for his Distinguished Service Order. The dreadnoughts did not sink, but reached port and underwent repairs.
The submarine was later transferred to Gibraltar for operations in the Mediterranean.
thumb|left|J1 being refitted at [[Cockatoo Island Dockyard in 1919]]
After the war, the British Admiralty decided that the best way to protect the Pacific region was with a force of submarines and cruisers. The hulk was scuttled in the ship graveyard off Port Phillip Heads at on 26 May 1926.