'MB' (iii) was the designation of Allied convoys (together with a numerical suffix) plying the route from Port Moresby to other Papuan destinations (March/November 1943).

The first of the series was MB.1 of 24/26 March 1943 from Port Moresby to Fall River with the 7,176-ton US Henry Dearborn and the 1,200-ton Australian commissioned transport Mulcra, and the last was MB.13 of 25/26 November 1945 from Port Moresby to Oro River with the 7,176-ton US Clarence King, 7,176-ton US Thomas Jefferson and 7,176-ton US William Hume.