Operation M-5

'M-5' was a Japanese anti-submarine sweep of the Malacca Strait (1/7 January 1945).

For this undertaking, the Imperial Japanese navy attached the submarine chaser CH-8 to the Southern Expeditionary Fleet, 15th Base Force, Submarine Chaser Division 11, which also comprised the submarine chasers CH-7, CH-9, CH-34 and CH-35, as well as the auxiliary submarine chasers Wakatake Maru and Miyako Maru.

Air support for the operation was provided by the 331st Air Group and the 936th Air Group.

In 6 January the minesweeper W-4 departed Singapore to make additional patrols in the 'M-5' patrol area with the auxiliary minesweepers Toshi Maru and Toshi Maru No. 2 as well as the auxiliary submarine chaser CHA-55.