Q1192 was one of 16 Harbour Defence Motor Launches (HDML) to be delivered to the RNZN in 1943. She was commissioned on 28 September 1943 and joined the 126th. Flotilla at Auckland . Her anti-submarine patrols covered the port approaches, the Hauraki Gulf and northwards to Cape Brett.
She was ready in March 1945 to be deployed to Manus Island but this was cancelled and she transferred to Wellington instead. She paid off from war service in October 1945 at Auckland, was disarmed and placed in reserve on a mooring.
In 1948 she returned to service and commenced duties on the ‘Tamaki’ run to Motuihe Isand. At this time she was reclassified as a Seaward Defence Motor Launch (SDML) and in 1950 was renumbered to P3554 and named Irirangi. The Tamaki services ended in August 1963: she was modernised and re-engined with Foden 8s, radar was added, and on 4 August 1964 she was commissioned as HMNZS Maroro for Fishery patrol duties.
Over the years Maroro performed many additional tasks; search and rescue, port visits, escorting visiting warships and in 1970 with Mako was guard-boat for HMY Britannia during the Royal Tour. She was then restricted to sheltered waters and in 1972 was dismantled for disposal. In July 1972 she was sold and went to Fiji as a tourist launch. She was wrecked on a reef on 27 August 1982 and became a total loss.