HDMLs Q1187 & Q1188 were shipped as deck cargo from Vancouver aboard SS Kootenay Park and arrived at Wellington on 30 April 1943. There they were unloaded by floating crane and underwent full commissioning trials.
Q1188 joined the 125th Motor Launch Flotilla based in Wellington and carried out routine patrols through to 1945. As the war came to an end in 1945 the launches were concentrated at Auckland to pay off. Q1188 arrived on 11 July. After paying off they were laid up at Pine Island in the Upper Waitemata. In July 1946 ownership passed to the Marine Department who was selling off war surplus. Once the Lend-Lease agreements were concluded the government put them up for sale. However, during the sale process the government realised their value and in February 1947 Q1188 was withdrawn from sale.
In 1949 the RNZN purchased the frigate Lachlan for use as the first survey vessel in RNZN commission. It was decided that two smaller vessels would be needed to assist her in the survey task which HDMLs would be suitable. Q1188 had been cannibalised for parts to keep the other HDMLs that were in service so she had to be rebuilt. This was completed in February 1950 and she was commissioned as SML 1188 and was sent to Wellington in March. After arriving in Wellington, she began a survey of Cook Strait. In April she was given the pennant number P3556.
A second launch was required for survey duty so that Auckland Coastguard’s Cutter No. 1, formerly Q1187 reverted to the RNZN on 29 May 1950 and was given the pennant number P3566 in October 1950. She was converted to SML in March 1951 and commissioned as a survey vessel on 21 March 1951. In April she proceeded to Wellington to carry out surveys of the Cook Strait. From then until 1979 both vessels carried out surveys right across the New Zealand coastline mostly by themselves or as a pair. They would also work with HMNZS Lachlan & Monowai.
In 1948 the Admiralty re-classed HDMLs as Seaward Defence Motor Launches [SDMLs]. The RNZN changed the classification in August 1949. The similar pennant numbers caused some confusion in signalling and the keeping of records. There is still today some uncertainty about which vessel is being referred to due to errors in recording the correct number. To try ad solve the problem for the signallers from May 1951 P3556 had [A] added and P3566 [B]. These were added to the hulls in 1953. The next change was to assign names to the SDMLs that were in service with the RNZN. Those SDMLs that were assigned to fisheries protection were assigned Maori names for fish while other vessels were given Maori names for sea-birds. On 21 July 1955 P3556A was renamed Philomel, P3566B was renamed Maori from the shore establishments. As per NO 14/56 of 19 January 1956 Philomel was renamed Takapu [Gannet] from October 1955. Maori was renamed Tarapunga [Black-backed Gull] also from October 1955. They would serve as survey vessels under these names until they were released from survey duty in 1979.
In November 1979 Takapu arrived at Auckland for paying off and was decommissioned in December. At this time the IPC vessels marked for survey duty were under construction at Whangarei and had been assigned the names Takapu & Tarapunga. Both SDMLs were repainted to the standard colour scheme and refitted for use by the RNZNVR. Takapu was renamed Kahawai II and was sent to HMNZS Toroa in August 1980. Tarapunga was renamed Mako II and sent to HMNZS Olphert in November 1980. In August 1982 Kahawai II left Otago and was dismantled for disposal. Mako II left Wellington in August 1983 for dismantling. Both vessels were sold by the RNZN in 1984 ending some 40 years of service with the RNZN which was well beyond their expected life in 1943.
When Kahawai ll was sold she renamed Takapu again and underwent an extensive refit. For many years worked out of Whakatane as a charter boat. She then moved to the Fiordland to continue her charter work. A helipad was added to the quarterdeck. She was in survey until earlier this year and is currently for sale, asking $200,000.