HMNZS Waikato ( F55 ) HMNZS " Waikato " ( F55 ) was a Leander Batch 2TA frigate of the Royal New Zealand Navy ( RNZN ) . She was one of two Leanders built for the RNZN , the other being the Batch 3 HMNZS " Canterbury " . These two New Zealand ships relieved British ships of the Armilla patrol during the Falklands conflict , freeing British ships for deployment . History . " Waikato " was ordered in 1963 for the RNZN after a delay of more than six years after the order for the Type 12 frigates " Otago " and " Taranaki " , which had proved successful in New Zealand service . A pressing need to replace the ageing cruiser Royalist and the RNZN ' s last two operational Loch class frigates , which carried outdated sonars and a / s weapons and were slow , resulted in an order for the " Waikato " in 1963 . The final decision to order the frigate also related to increasing tension between , Britain and Indonesia over Indonesian threats to the sovereignty of Sarawak . Delivered in 1966 , " Waikato " was a fully armed batch 2 Leander , whose armament included a GWS22 Seacat missile system , a landing pad and helicopter for a Wasp helicopter intended to monitor and attack submarine targets with torpedoes and a variable - depth sonar , which proved a mixed success in the RNZN service . The main hull sonar was the standard RN 177 of the 1960s . For the first 9 years of its RNZN service the Waikato operated around NZ and with the ANZUK naval squadron based at Singapore , which continued for three or four years after the official British withdrawal from Singapore in 1971 in reduced form in 1971 – 75 in the company of 5 or 6 RN frigates and destroyers . In 1975 – 77 " Waikato " was given an extensive mid life refit , and essentially modified to the specifications of HMNZS Canterbury with the mortar and VDS wells suppressed and replaced by an enlarged helicopter landing pad , intended for Lynx helicopters that were never ordered and a closed circuit TV system to monitor helicopter operations from the flightdeck . Surface and Navigation radar was also updated to current RN standards a rather inexpensive alteration . At the time the RN had already rebuilt its early Leanders with Ikara missile and computer action automation of weapon systems and the second batch Leanders of the same type as Waikato were have their gun turret replaced with Exocet missiles , receiving additional Seacat launchers and improved C3 . The cost of the Ikara RN modernisation was probably about five times the Waikato ' mid life update and a refit equivalent to the batch 2 RN Leander would have cost ten times as much , ( refer Janes FS 1981 - 2 for cf refit costs ) . Reentering service under the Command of Captain Ian Bradley RNZN , " Waikato " had a colourful late 1970s . It was involved in a challenging and marginally risky rescue of a seriouly injured fishermen on a Soviet trawler Ardatov when a Wasp was launched in rough sea conditions , flown by Lt Joe Tunicliffe to pick up the man from a trawler . Escorting the USN Thresher class SSN Haddo into Auckland harbour in Jan 1979 , the Waikato faced an armada of anti nuclear protest yachts , which attempted to block the passage of the possibly nuclear armed and certainly nuclear powered USN attack sub . The Waikato ran into the harbour at 30 knots ahead of the Haddo , with the Waikato ' s Wasp helicpter and another RNZN Wasp in company , deployed over the protest yachts to create downdraft which destabalised the protest yachts , and tipped several over in a controversial move which secured the rapid passage of the Haddo to its berth . No one was hurt . While appreciated by the US Navy and crew of the USN hunter killer , the move was regarded as aggressive by the certain NZ politicians and was condemned by the protestors . The approach was never adopted again . " Waikato " deployed to Pearl Harbour for work up with USN fleet units and performed well in exercises with the US and Canadian fleet . Decommissioning . HMNZS " Waikato " was decommissioned from the Royal New Zealand Navy in 1998 and bought from the Government for $ 1 . She was stripped in the Northland port of Opua and sunk off the coast of Tutukaka on 18 December 2000 as an artificial reef . In 2002 , the sunken " Waikato " ' s bow was separated from the rest of the ship in heavy weather .