Natsushima-class minelayer (1933)

The Natsushima-class minelayer (夏島型敷設艇,) was a class of minelayers of the Imperial Japanese Navy (IJN), serving during and after the 1930s through World War II. Their design was based on the Tsubame-class minelayer, but with increased armament.

Natsushima class
Project number H5. Three vessels were planned under the Maru 1 Programme. However, the third ship, Sarushima, was used as a diesel engine experiment ship.

Natsushima (夏島)
 * 24 December 1931: Laid down at Tōkyō Ishikawajima Zōsen.
 * 24 March 1933: Launched.
 * 31 July 1933: Completed.
 * In 1934: Rebuilding after the Tomozuru Incident.
 * In 1938: Sortie for the Second Sino-Japanese War.
 * 1941-1943: Sortie for the naval mine laying at Japan Mainland.
 * 10 December 1943: Dispatched to southeast area.
 * 22 February 1944: Sunk by USS Stanly, USS Charles Ausburne and USS Dyson off Kavieng -2.66667°N, 149.66667°W.
 * 30 April 1944: Removed from naval ship list.

Nasami (那沙美)
 * 19 January 1933: Laid down at Harima Zōsen.
 * 26 March 1934: Launched.
 * 20 September 1934: Completed.
 * In 1938: Sortie for the Second Sino-Japanese War.
 * 1941-1943: Sortie for the naval mine laying at Japan Mainland and convoy escort operations at East China Sea.
 * 31 December 1943: Dispatched to southeast area.
 * 1 April 1944: Sunk by air raid at Rabaul.
 * 10 April 1944: Removed from naval ship list.

Sarushima class
Project number H5B. She was built as diesel engine experiment ship. Her results were made use of in the Sokuten-class minelayer.

Sarushima (猿島)
 * 28 March 1933: Laid down at Mitsubishi, Yokohama shipyard.
 * 16 December 1933: Launched.
 * 20 July 1934: Completed.
 * In 1938: Sortie for the Second Sino-Japanese War.
 * 1941-1944: Sortie for the naval mine laying and convoy escort operations at Japan Mainland.
 * 4 July 1944: Sunk by air raid off Otōto-jima.
 * 10 September 1944: Removed from naval ship list.