The was a class of minesweepers of the Imperial Japanese Navy (IJN), serving during the 1930s and World War II. 6 vessels were built in 1931-36 under the Maru 1 Keikaku. They have two sub classes, this article handles them collectively.

Background Improved model of the No.1-class. The IJN tried to a small hull than No.1-class to give a performance the same as No.1-class. And this attempt failed when the vessels were discovered to be top heavy by an investigation of the fleet in the aftermath of the Tomozuru Incident.

Ships in classes No.13 class Project number I3A. 4 vessels were built in 1931-1934. No.15 and No.16 were behind with the completed by the Tomozuru Incident. They had clipper-bow. Ship Builder Laid down Launched Completed Fate No.13. The same shall apply hereinafter. Fujinagata Shipyards 22 December 1931 30 March 1933 31 August 1933 Sunk by bombardment from Netherlands pillbox at Tarakan Island on 12 January 1942. Decommissioned on 30 November 1945. No.14 Ōsaka Iron Works 22 December 1933 20 March 1933 30 September 1933 Sunk by bombardment from Netherlands pillbox at Tarakan Island on 12 January 1942. Decommissioned on 30 November 1945. No.15 Fujinagata Shipyards 6 April 1933 14 February 1934 21 August 1934 Heavily damaged by USS Tilefish on 5 March 1945, later agrounded. Decommissioned on 10 May 1945. No.16 Mitsui, Tama Shipyard 20 June 1933 30 March 1934 29 September 1934 Sunk by air raid off Makassar on 11 September 1943. Decommissioned on 11 November 1943.

No.17 class Project number I3B. 2 vessels were built in 1935-1936. Improved model of the No.13-class. About their appearance, bow was changed to double-curvature bow and fitted Kampon geared turbine. Ship Builder Laid down Launched Completed Fate No.17 Ōsaka Iron Works 28 January 1935 3 August 1935 15 January 1936 Decommissioned on 20 November 1945. Scrapped on 1 September 1948. No.18 Mitsui, Tama Shipyard 2 February 1935 19 September 1935 30 April 1936 Sunk by air raid off Hainan on 26 November 1944. Decommissioned on 10 January 1945.

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Footnotes

Bibliography Ships of the World special issue Vol.45, Escort Vessels of the Imperial Japanese Navy, , (Japan), February 1996 The Maru Special, Japanese Naval Vessels No.50, Japanese minesweepers and landing ships, (Japan), April 1981