A United States Navy submarine sank her in the Philippines in 1944, killing 61 of the people aboard.

She also had an exhaust steam turbine, which drove the same propeller shaft, but via double reduction gearing.

The combined power of her reciprocating engine plus exhaust turbine was rated at 171 NHP.

[1] On 15 January 1941, Sinkyo Maru was assigned to minelaying operations as an auxiliary gunboat.

On 31 January her bridge was repaired; on 4 February she left Sasebo, and the next day she reached Kakeromajima in the Amami Islands, off the southern coast of Kyushu.

[1] On 30 May 1942, the US Navy submarine USS Pompano crippled the 7,983 GRT troopship Atsuta Maru.

Atsuta Maru sank on 3 June, about 50 nautical miles (93 km) east of Okinawa.

Between 20 and 24 December she made a round trip to Kakeromajima and back to unload supplies, and then sailed in East Convoy No.

She was temporarily fitted with anti-submarine protection equipment; an upgrade to her wireless telegraph; and an additional 13 mm machine gun.

[1] In Tsingtao, Sinkyo Maru embarked troops, vehicles, supplies and provisions of the 41st Division.

They called at Palau from 22 to 26 February, and then continued as the Fourth Transport Echelon, with the destroyers Satsuki and Fumizuki joining Yūgure to reinforce their escort.

[1] Early in April 1943, Sinkyo Maru was assigned to coastal defence of the east coast of Japan.

In May she patrolled north via Kushiro on Hokkaido to Paramushiro in the Kuril Islands; returning to Yokosuka in June.

On 16 February she left Moji as part of Convoy Mota-03, which included six merchant ships, and was escorted by the Namikaze and minesweeper Tian Maru.

[1] On 20 March, Sinkyo Maru left Manila in Convoy H-22, bound for Halmahera in the Maluku Islands.

On 23 March, in the Basilan Strait, the auxiliary submarine chaser Kyo Maru joined H-22; relieving W-30; which detached.

On 24 March, off Mindanao, the US Navy submarine USS Bowfin made radar contact with H-22.

At 23:48 hrs Bowfin fired her first torpedo salvo, which sank the cargo liner Bengal Maru.