Tony Davies told a select committee at Parliament the decision to bring HMNZS Otago out of care and custody arrangements in the third quarter of 2026 followed the sinking of a specialist dive and hydrographic vessel, the Manawanui off Samoa.
"Before you put it back to sea, it has to have quite a bit of work and money spent on it," Davies added.
"It requires tens of millions of dollars."
The Otago can operate in the country’s exclusive economic zone, the Southern Ocean and the Pacific, on tasks such as patrolling, surveillance, search and rescue, disaster relief and peacekeeping support, the Defence Force said on its website.
The ship was one of three idled in 2021 and 2022 as the military struggled to man them amid historically high levels of attrition that have since dropped off, with sufficient staff for the Otago after the Manawanui sinking.
On October 6 last year, the ship ran aground on a reef off the south coast of Upolu and then sank. All 75 passengers and crew survived. The New Zealand government paid $6 million in compensation to Samoa.
Davies said the Navy used satellites and uncrewed system to monitor a huge maritime area but the presence of a ship was indispensable to help monitor transnational serious organised crime and illegal fishing.
The government, which has committed to increase defence spending over the next eight years, has boosted deployments as tension grows worldwide.
Last month, its largest ship, the oiler Aotearoa, made a rare transit through the sensitive Taiwan Strait.
