Here's a bit of the background into the RNZN's involvement in Antarctica:
Pukaki and Hawea escorted the Antarctic supply ship Endeavour from Bluff to the edge of the pack ice on the Endeavour's (this was
the first Endeavour - a converted dan layer) first voyage south in late December 1956. To relieve the USN weather picket ships on their station at 60 south 170 east, 900 miles south of Bluff, the RNZN fitted
Rotoiti out as a weather picket ship in 1961. On 2/10/61 she sailed from Auckland on the first patrol, to provide weather information and be on emergency standby for the US aircraft flying between Christchurch
and McMurdo. Based at Dunedin, each patrol was on station for 10 - 12 days, with usually two patrols in October - November, and one or two in January - February, the season ending early in March. Weather and sea
conditions were usually bad to severe, with icebergs, snowstorms and icing up among the natural hazards. Rotoiti did three tours in the 1961-62 season, two in late 1962, and her last two ending 3/12/63. Pukaki
was similarly modified and took over in mid 1/64 for two tours. 1964-65 was the last season, Pukaki doing five tours including one over Christmas. Her last patrol ended on arrival at Dunedin 23/2/65. Both ships
were withdrawn from service within months on account of poor hull condition.
Endeavour's last trip was in 1961. She too was taken off Antarctic duties due to poor hull condition. She was replaced by the
next Endeavour (former USS Namakagon - ex-Patapsco class oiler). This Endeavour carried a million gallons of avgas a year for the US Navy as well as supplies for McMurdo and Scott Bases. This Endeavour did the
Antarctic support duties for Operation Deep Freeze from 1962 until 1971. At that point, the RNZN decided against any further committment.
In June 1966, HMNZS Taranaki, with a reduced crew, sailed to 60 South to act as a weather picket for a
mercy dash to Antarctica by a military aircraft to uplift a sick person and transport back to Christchurch.