At the beginning of March 1942 the Mataisailed to Suva, where she was joined by the danlayers Kaiwaka and Coastguard. At that time the United States Navy was preparing to establish a base and fleet anchorage in Nandi Waters at the western end of Viti Levu. Lieutenant C. C. Lowry, RN, in charge of a Royal Australian Navy survey party, arrived at Suva on 12 March and surveyed the Nandi area, assisted by Lieutenant-Commander A. D. Holden, RNZNR, commanding officer of the Matai, and his ship's company. During the first week of April the Matai, Kaiwaka, and Coastguard, as danlayers, co-operated with the United States ships Gamble, Ramsay, andKingfisher which laid protective minefields in Nandi Waters. In company with the Muritai, the Kaiwakaand Coastguard returned to Auckland on 25 April. HMFS Viti arrived back at Suva early in April, relieving the Moa which sailed for Auckland. TheGale also returned to Suva on 25 May but a month later was ordered to Noumea.

For the next five months the Matai and Viti, in co-operation with aircraft of the RNZAF, maintained almost continuous anti-submarine patrols and provided close anti-submarine escort for the increasing number of troop transports and supply ships arriving at and sailing fromSuva. This monotonous round of duty was scarcely relieved by infrequent and unverified reports of submarines.

From the beginning of August 1942, the start of the Solomon Islands campaign, the 25th Minesweeping Flotilla was assigned to anti-submarine duties at Noumea, the forward base of comsopac, PAGE 267whose headquarters was later established there. The Moa and Kiwi joined the Gale atNoumea in August-September and the Matai (SO 25th M/S Flotilla) arrived on 25 October after a short refit in New Zealand. She had been replaced at Suva by the Tui. TheMoa was detached to Norfolk Island at the beginning of October and was away for two months.

Norfolk Island, which is almost equidistant from New Zealand, Australia, and New Caledonia, was being developed as a base for anti-submarine patrols and a staging depot for aircraft. A start had been made in September on the construction of an airfield and New Zealand was furnishing a battalion as a garrison for its defence. The troops were carried in the Wahine which, escorted by HMNZS Monowaiand the United States destroyer Clark, made two voyages from Auckland to Norfolk Island during October 1942. The equipment and supplies for the garrison went in the steamerWaipori, 4282 tons, whose discharge was difficult and prolonged owing to the lack of shore facilities. While she was lying at anchor off the island, anti-submarine protection was given by the Inchkeith and Sanda, which had come fromAuckland, and the Moa from Noumea. During the next eight months the Inchkeith, Sanda, and Scarba were regularly employed on anti-submarine patrols while supply ships were discharging at Norfolk Island. In October 1943 the Scarbagave protection to the Cable Enterprise¹ while that ship was repairing the Norfolk Island – Suva submarine cable.

At the end of October 1942 the Naval Board, with the approval of the Government, offered the 25th Minesweeping Flotilla to comsopac for service wherever it might be wanted in the Pacific. The offer was accepted and on 12 December theMatai, Kiwi, Moa, and Tui sailed from Espiritu Santo, in theNew Hebrides, for the Solomon Islands, where theGuadalcanal campaign was then nearing its climax. They arrived in Tulagi harbour on the 15th and, four days later, began a tour of duty that kept the flotilla hard at work in and about the Solomons for two and a half years.² The Galejoined the flotilla in February 1943.

On 16 December 1944 Commander P. Phipps (formerly of the Moa), who had succeeded Commander Holden as Senior Officer 25th M/S Flotilla, assumed command of the new corvette Arabis, which relieved the Matai. The latter ship returned to New Zealand and was paid off at Wellingtonon 25 January 1945. The reduced flotilla remained under the operational control of comsopac for another seven months, mainly in the Solomon Islands. The Kiwi was detached for duty at Suva for a few weeks and the Arabis was stationed in the Funafuti (Ellice) Group from 6 April to 28 May 1945. The former vessel returned finally to New Zealand in May and the Arabis and Tui in July 1945.

HMFS Viti, while under the operational control of the New Zealand Naval Board, did two years' service on anti-submarine patrols at Suva, varied only by rare visits toSamoa, the New Hebrides, and Guadalcanal on escort duty and a three months' refit at Lyttelton in 1943. By the middle of 1944 the widely scattered islands under the jurisdiction of the High Commissioner for the Western Pacific had been freed from the enemy and there was urgent need of another supply vessel to assist the Awahou,¹ which earlier had been made available by the New Zealand Government. Approval to disarm the Viti and refit her for that purpose was given bycomsopac and the Naval Board and the work was done atLyttelton.

On the morning of 19 December 1942 HMNZS South Seawas sunk in Wellington harbour as the result of a collision with the inter-island steamer Wahine, which had left the wharf a few minutes before on passage to Lyttelton. TheSouth Sea, patrolling in company with the Rata, was steering south by west towards Point Halswell and the Wahine was steaming about east by north to pass well clear of the point. Thus their respective courses were almost at a right angle to each other. The South Sea was badly holed when theWahine struck her on her starboard side and the man at the wheel was slightly injured. While the Rata took the damaged ship in tow, the tug Toia went alongside and tried without success to control the inrush of water by means of a powerful pump. The South Sea sank about a mile from Point Halswell after her crew had been taken off by the Rata.

The board of inquiry found, inter alia, that from the time the South Sea sighted the Wahine there was a definite risk of collision according to Article 19 of the regulations for preventing collisions, that the commanding officer was in error in not taking any bearings of the Wahine, and that he should have acted in accordance with Articles 22 and 23 of the regulations.² The board also expressed the view that (a) had the Wahine held her original course and reversed engines at the same time as she did in fact reverse them, a collision probably would not have occurred; (b) had she held both her course and speed there was a strong possibility that a collision would have occurred; and (c) that the Wahinewas correct in assuming that a collision was practically unavoidable and that action should be taken in accordance with the note to Article 21 of the regulations, but that ‘she was probably incorrect in altering course to starboard’.³Excepting (a), which was considered to be at odds with the evidence, and (c), the last clause of which was considered contentious, the Naval Board accepted these findings. A civil Court of Marine Inquiry opened on 24 February 1943, but did not proceed when it was ruled in accordance with the Shipping and Seamen Act 1908 that it had no jurisdiction where one of His Majesty's ships was concerned.

The ‘double L’ sweepers spent many months of monotonous service on the New Zealand coast, lengthy spells of harbour duty being varied only by training cruises from port to port. The efficiency of their constant training was not put to a practical test for no magnetic mines were ever found or suspected in New Zealand waters. A fourth composite minesweeper, the Tawhai, built at Auckland, was delivered on 24 April 1944 but was not commissioned for service.

With a view to converting them for use as magnetic minesweepers, the Naval Board in June 1942 had got Cabinet authority to purchase two wooden steamers, theWairua for £25,000 and the Ruawai for £4000.⁵ On the advice of the Captain Superintendent of the dockyard, however, it was decided not to buy the latter vessel. TheWairua arrived at Lyttelton at the end of August 1942 for conversion and there she remained for more than two and a half years.

In October 1942 orders were given to stop all work on the vessel. The Government had recently requisitioned six coastal vessels for comsopac for use as supply ships in the South Pacific islands and it was thought that the Wairuashould be returned to trade. Three months later, however, War Cabinet decided against this and work on the vessel was resumed. Progress was intermittent and slow, and at the beginning of October 1943 work was again stopped, probably for the reason that an additional magnetic minesweeper was quite unnecessary.

The Naval Board then decided that the Wairua should be adapted to service the outlying islands in the Auckland area, but when a prospective purchaser inquired about her, the Board informed the Treasury that it had no objection to the sale. Tenders called for brought one offer of £2500 which was not accepted and the vessel was laid up. In March 1945 the Wairua was sold to the Marine Department for £1000 for use as a ferry steamer between Bluff and Stewart Island. The cost of the purchase and partial conversion of the little vessel was £32,887 17s. 4d., and this sum, less the £1000 paid by the Marine Department, was written off as ‘nugatory expenditure’.

The fishing trawlers Nora Niven and Phyllis¹ were purchased in 1942 and fitted out at Lyttelton as danlayers, the intention being to employ them at Auckland in place of the Kaiwaka and Coastguard which were to be stationed atWellington. They were commissioned on 11 January 1943 but when they arrived at Auckland an inspection revealed numerous defects in both vessels, one of which was 36 years and the other 31 years old. The selection of these aged vessels was criticised by the Captain Superintendent of the dockyard, who remarked that ‘… if vessels are old enough their condition will be poor and expenditure will have to be large to bring them up to something like service standard.’ Repairs were not completed and little or no use was made of the Nora Niven and Phyllis, which were paid off in February 1944 and later sold.

When the first of the New Zealand-built steel minesweepers came into service in 1943, the owners of coastal vessels requisitioned in more difficult times began to press for the release of some of their ships. On 13 March 1943 the Anchor Shipping and Foundry Company, of Nelson, asked for the return of the Rata, but the Prime Minister replied that she would have to be retained for some time to come. A few days later the Controller of Shipbuilding lent support to the Anchor Company by asking that the Rata be released as soon as the first steel minesweeper had been commissioned. The Naval Secretary informed him that it would not be possible to return the Rata until the last of the thirteen steel minesweepers had been completed.

This decision was reviewed at a conference on 28 September 1943 attended by the members of the Naval Board, the Naval Officers-in-Charge at the main ports, and staff officers. In view of the improved strategic situation in the Pacific and the need to conserve manpower, it was agreed that the last four steel minesweepers on the building programme should be cancelled, that the Rata and possibly the Nora Niven and Phyllis be returned to trade, and that a start be made with the sweeping of the defensive minefields laid in 1942. These recommendations were approved by the War Cabinet next day.

The Rata was paid off at Port Chalmers on 11 October 1943 and the two trawlers at Auckland in February 1944. The Futurist was withdrawn from minesweeping duties and converted into a boom gate vessel at Wellington.

HMNZS Aroha, first of the new steel minesweepers, had been commissioned by Lieutenant Peter Petersen, RNZNVR,³at Port Chalmers on 12 May 1943. Then followed theAwatere, commissioned at Wellington by Lieutenant E. M. C. Stevens on 26 June, the Hautapu by Lieutenant-Commander Ralph-Smith, RNZNVR,⁴ on 28 July, the Maimai by Lieutenant Watson, RNZNR,⁵ on 15 September, and theWaipu by Lieutenant Blair, RNZNVR,⁶ on 17 November. At the end of 1943 there were twenty-four anti-submarine and minesweeping vessels and two danlayers in service.

With the approval of the War Cabinet, the Naval Board on 31 December 1943 ordered the sweeping of the independent minefield in the Bay of Islands. This was done by the Inchkeith, Killegray, Sanda, and Scarba and the danlayers Coastguard and Kaiwaka, three motor-launches being employed to sink the mines. By the end of February 1944 all but nine of the 258 mines laid in October 1942 had been swept: the others probably had broken adrift and gone out to sea.

The new steel minesweeper Pahau was commissioned by Lieutenant Gray, RNZNVR,¹ on 12 February 1944 and theWaima by Lieutenant Stevens, RNZNVR,² on 28 March 1944. The A/S M/S forces were then organised as follows:

On 16 May 1944 a start was made with the sweeping of the defensive minefield laid in March 1942 across the main channel in Hauraki Gulf. This major task, known as Operation PM, was carried out by the 7th Trawler Group (Senior Officer, Lieutenant-Commander Mackie, RNR,² inSanda) assisted by the Muritai from the 97th Group, the danlayers Kaiwaka and Coastguard, and three motor-launches as mine sinkers. As the mines were spaced 150 to 170 feet apart and there was only a mile between the two lines, one of which was a zigzag, special precautions were taken to restrict the number of mines cut in one sweep and to increase the chance of a ship sweeping any mine that might be tripped out of the sweep of her next ahead.

The Kaiwaka and Coastguard, the former acting as a sweeper, worked alone for the first six days to make sufficient clearance for the other ships to manoeuvre. In that time the danlayers swept and destroyed 22 mines and, with the Muritai, another 22 during the next three days. The 7th Trawler Group then joined in and, despite delays caused by bad weather and unfavourable tides, a total of 394 mines had been disposed of by 25 June. A second sweep of the area accounted for one more mine, and two further check sweeps were made without result. Two mines were known to have broken adrift before the clearance began and underwater explosions in the course of sweeping probably accounted for the remainder of the 400 mines originally laid. In his report to the Naval Board, the Naval Officer-in-Charge Auckland said the clearance of the minefield in a little more than two months ‘reflected great credit on Lieutenant-Commander Mackie and all who took part in the operation’.

HMNZS Waiho, eighth and last of the new steel minesweepers completed for service, was commissioned atPort Chalmers on 3 June 1944 by Lieutenant Monaghan, RNZNR.³ She joined the 97th Minesweeping Group atAuckland, replacing the Muritai which became a tender to HMNZS Tamaki for the sea training of new entries.

Lieutenant-Commander Seelye, RNZNVR,¹ was appointed in command of the Arabis and Lieutenant-Commander Rhind, RNZNVR,² to the Arbutus. Five other New Zealand officers were selected for each ship, in which most of the ratings were also New Zealanders.

The Arabis was commissioned on 22 February 1944 and sailed with an Atlantic convoy as far as the Azores Islands. Thence she proceeded by way of Bermuda, the Panama Canal, San Diego, Pearl Harbour, and Suva, arriving atAuckland on 15 August. The Arbutus, which was commissioned on 16 June 1944, sailed from Greenock on 1 August in company with a convoy and followed the same route as the Arabis.

Unfortunately, the Arbutus was severely damaged when she grounded on a reef off Viwa Island, the westernmost of the Fiji Islands, on 7 October. A ship had to be sent to assist her to Suva, whence she was towed by HMNZS Aroha toAuckland, arriving there on 27 October. A survey showed that, in addition to the loss of the rudder blade, the bearing casting of the rudder stock had been fractured, the tail shaft bent, the propeller blades broken and bent, and the ship's bottom ‘set up’ for a length of about 25 feet. The Arbutusremained at Auckland for nearly three months awaiting the making of a new rudder and several castings and the arrival of a new propeller and tail shaft from England. She was then towed to Lyttelton, where permanent repairs were completed by the end of April 1945. Lieutenant N. D. Blair was appointed to command her in February 1945. As her services were not needed by the 25th Minesweeping Flotilla, the Arbutus was lent to the British Pacific Fleet. She was fitted out at Sydney as a radar servicing and repair ship and did duty in the Fleet Train until the end of September 1945. After her return to New Zealand she was employed for a brief period on a scientific expedition to the Three Kings Islands.

The Sanda, Scarba, Killegray, and Inchkeith of the 7th Trawler Group, with the Waipu, Wakakura, Kaiwaka, andCoastguard as danlayers, spent eight days sweeping the Cradock Channel area off the north-west end of Great Barrier Island but no mines were found. Starting again on 8 April, the sweepers searched most of the area extending north and west of Moko Hinau to the swept channel between Maro Tiri and the mainland. No mines had been found when sweeping ceased temporarily on 21 May.

Two months later a signal was received from the British Naval Officer-in-Charge at Wilhelmshaven giving the number of mines (228) and the approximate positions in which they had been laid. This was supplemented by a copy of the track chart of the German raider Orion. Working on this precise information, the sweepers carried out a further search of the northern area, but no mines had been found when operations ceased on 17 October 1945. The sweeping of the eastern approaches to Hauraki Gulf on either side of Cuvier Island was postponed for five months.

The cause of this long delay and of many of the interruptions since March 1945 was a shortage of coal, which immobilised the minesweepers. Since there was no prospect of an improvement in coal supplies and shipowners were pressing for the reopening of the Cuvier Island channels, the oil-burning corvettes Arabis and Arbutus were temporarily fitted out as minesweepers at a cost of about £1350, and the coal-burning ships of the 7th Trawler Group were ordered to be paid off into reserve.¹ The Waiho, Waima, andWaipu, allocated as danlayers, were coal-burners and the Ministry of Mines guaranteed a supply of 500 tons of coal a month to keep them at sea.

By that time the minesweeping flotillas, built up at great cost during the six years of war, were being rapidly dispersed. Demobilisation was proceeding rapidly, and within a year after VJ Day most of the little ships had been paid off to ‘await disposal’.

Beginning with four vessels in 1939, the minesweepers had attained their maximum strength four years later when there were twenty-six in commission, two in reserve, and others nearing completion. Most of them were dual-purpose vessels equipped for anti-submarine duties as well as minesweeping. It was the fortune of war that only the Kiwi, Tui, and Moa as anti-submarine vessels ever got to close grips with the enemy. The work of the port minesweepers for the greater part was to maintain the swept channels in the approaches to the main harbours. This and anti-submarine patrols and escorts were their long, continuous tasks, and they were well done. The performance of the minesweepers in the Second World War is one of the proud traditions of the Royal New Zealand Navy.

HMNZS Hautapu was recommissioned in April 1946 to take part in the ‘Canterbury Project’, a scientific investigation of long-range radar observations undertaken by the Department of Scientific and Industrial Research at the request of the British Government. Based at Timaru, theHautapu made several offshore cruises, but so much time was spent in harbour that her crew became unsettled. She was paid off at Auckland in April 1947 and transferred to theMarine Department, which provided a crew for the few remaining months of her scientific service. The Hautapu was sold later for £17,500 to New Zealand Fisheries Ltd., ofWellington, who had already purchased the Waikato (later renamed Taiaroa).

The Aroha, Waiho, and Waima were sold to Red Funnel Fisheries Ltd. of Sydney for a lump sum of £50,000, and theAwatere and Pahau to A. A. Murrell of Sydney for £30,500. The Maimai went to the Maimai Trawling Company Ltd. ofWellington for £15,000, and the Waipu was bought by Sanford Ltd. of Auckland for £16,500. The average cost of each of these vessels when built was £73,230.

The Wakakura, paid off in October 1945 after nearly twenty years' service in the New Zealand Naval Forces, was sold for £2000 in 1947 to the Tasman Steamship Company, which had been formed by returned servicemen. They later bought the Fijian vessel Viti. The Muritai was sold to the Devonport Steam Ferry Company Ltd. of Auckland for £8000. The danlayer Kaiwaka, which was found to be in bad condition, was partly repaired before being returned to the New Zealand Refrigerating Company Ltd., to whom £13,343PAGE 278was paid in lieu of full restoration and £9000 for loss of value.

The composite-built sweepers Hinau and Rimu were retained in reserve and the Manuka was leased to the Chatham Fishing Company, a group of returned servicemen. Special conditions of the charter were that she would be used only in New Zealand waters and released to the Navy if required in the event of an emergency. The corvettes Arabisand Arbutus were returned to the Royal Navy in 1948 when the six Loch class frigates Hawea, Kaniere, Pukaki, Rotoiti, Taupo, and Tutira were purchased for the Royal New Zealand Navy.