Culture and heritage

Maritime heritage

Submarine K-IX (1922-1945)

The search for the K-IX

The NSW Heritage Office led a search for the intriguing 64.50 metre long Dutch submarine on 20 July 1999, 54 years to the day after the wreck was sold at auction. The search was successful with the discovery of the wreck lying under three metres of sand on Submarine Beach, south of Seal Rocks, New South Wales, Australia.


K-IX ashore c.1946 Photo: Bob Anderson

K-IX ashore c.1946 Photo: Bob Anderson

The former Royal Netherlands (Dutch) Navy submarine K-IX was built in 1922 at the K.M. de Shelde yard at Flushing, Holland. In a remarkable career, the submarine was finally wrecked on a desolate beach south of Treachery Head, Seal Rocks in 1945. It is the only known submarine wreck in NSW, apart from the still unlocated Japanese midget submarine that was one of three that attacked Sydney Harbour. Escaping the Japanese advance of Java in 1942, the K-IX fled to Fremantle and was finally based at Sydney.

The submarine was extensively damaged when a torpedo passed underneath it and destroyed the ex-ferry Kuttabul during the Japanese midget submarine raid of 31 May, 1942. Commissioned as a unit of the Royal Australian Navy, the submarine became an expensive liability requiring constant servicing. Finally paid off in 1944, the hull was converted to carry diesel oil.

The vessel ran ashore on 8 June, 1945 after slipping the tow of its transport, the RNN Abraham Crijnsen, on a voyage to Brisbane. The wreck was bought at auction on 20 July, 1945 for £985 but salvage attempts were incomplete. The K-IX wreck was last sighted in the 1980's following sand scouring, but is usually buried under several metres of beach sand.


The submarine lies in the tidal zone of Submarine Beach, named in honour of the vessel's resting place. This beach was originally known as Fiona Beach following the loss of the iron steamer Fiona in 1882. That wreck site lies 3km south of K-IX.

Wreck site condition


The K-IX ashore in 1945. Courtesy: Norm Peters Collection

The K-IX ashore in 1945. Courtesy: Norm Peters Collection

While not visible, photographs of the wreck when exposed suggest that the external hull plating has deteriorated extensively. It is conceivable that the continually buried lower hull might be retained to a greater degree. Deterioration of the upper casing plating reflects its proportionately thin manufacture. The internal pressure hull would be expected to be in better condition due to its manufactured strength and greater metal thickness.

The submarine remains, exposed in 1974. Note the spare anchor 'on deck' and circular access hatches into the pressure hull.

The submarine remains, exposed in 1974. Note the spare anchor "on deck" and circular access hatches into the pressure hull.

Importance of the K-IX submarine

The K-IX survives as a rare archaeological site type in Australia. It retains the potential to document World War One era submarine technology should the remains become exposed for detailed study. The site is ideally sited to be incorporated into a local historic shipwreck interpretative trail. This could be achieved through the establishment of educational signage close to the wreck site.

Listing information

The K-IX is a gazetted Historic Shipwreck, (24 October 1991), under Section 4 of the Commonwealth Historic Shipwrecks Act 1976. The listing applies to the shipwreck and all relics associated with the shipwreck.


  • Heritage Office, NSW Shipwreck database, accessable through the Australian National Shipwreck Database
  • Fant, Capt J.,1945 Casualty - oil tanker-converted submarine. Salvage report prepared for Commonwealth Marine Salvage Board, 19 June, 1945. National Archives, Melbourne, MP 456/4, Item 1945/130.
  • Gillette, R.,1999 Dutch submarine K-IX. Australian Warship Review, Vol.3 April/May. 1999. Pp.21-22.
  • Smith, T.,2000 Submarine K-IX: Conservation Management Plan. Heritage Office, Sydney, NSW, Australia
Page last updated: 31 August 2012