In the early 1920s Australia was gifted six J class submarines from the Royal Navy. These were the latest and largest submarines built by the RN for service in World War I. They were competent but were in service with the Royal Navy for only a short time before the end of the war. Once in Australia they were placed into service but there was little appetite for submarines or in fact any other military endeavour in the early ‘twenties’. The world was exhausted from a long and dirty war followed by a devastating Influenza Epidemic. The J class boats were soon retired and sunk as breakwaters or scuttled in the ship graveyard area off the mouth of Port Phillip Bay.Popular diving sites in Ships Graveyard outside the rip between Point Lonsdale and Barwon HeadsCircular brass plaque inscribed with J5 North Sea 1917 1918 made from a piece of navigational equipment used on the submarine J5 mounted on woodSubmarine J5 North Sea 1917 - 1918j class submarines, j5, ships graveyard, port phillip

HMAS Una was a Royal Australian Navy sloop that began its life as the German motor launch Komet. The ship, and her 57 crew, was captured by an infantry detachment of the Australian Naval and Military Expeditionary Force 9 October 1914, with no loss of life. Komet was then sailed to Sydney as a prize. During the time in which the Una was in service under Australia, the sloop was used as a Patrol and General Purpose Vessel. The sloop was used to patrol the areas of New Guinea, New Britain, New Hebrides and Malayan waters. After World War I, Una was decommissioned and taken to Port Phillip Bay, renamed Akuna and used as a pilot vessel. She was finally broken up in Melbourne in 1955.After World War I, HMAS Una was decommissioned and taken to Port Phillip Bay, renamed Akuna and used as a pilot vessel. She was finally broken up in Melbourne in 1955.A sclae drawing showing side view of the double screw passenger steam boat 'Komet' which was captuered by the RAN in WWI Doppelschrauben Passagierdampfer Aussen Haut [Double Screws, Passenger Steam Boat, Outside Hight]akuna, ppps, port phillip, hmas una, ran