New Zealand Navy ship HMNZS Manawanui has arrived in Tonga where it will be used to support divers who are working to confirm the discovery of a wreck as the sunken ferry Princess Ashika.
The navy ship battled ferocious weather with 50-knot winds and waves of up to five metres on its seven-day journey from Auckland. While its deck was awash with water for most of the journey, it is not thought to have suffered damage.
Manawanui commanding officer Lieutenant Commander Phil Rowe said on Saturday the relentless weather was the worst he's experienced in his 24-year navy career.
Because of the rough conditions, it will be at least Monday before the ship can sail to the site of the wreck, carrying navy divers already based in Tonga.
Once there, the ship will provide a stable platform for the deployment of a remotely operated vehicle which can provide photographic proof of whether the wreck on the ocean floor is that of the Princess Ashika.
Lieutenant Commander Andrew McMillan says the vessel will stay at the site of the sinking for at least one night.
The Princess Ashika capsized on 5 August about 90km northwest of the capital Nuku'alofa. Two bodies have been recovered, 93 people are missing, presumed dead, and 54 survived.
On Friday, Lieutenant Commander McMillan reiterated that the dive teams do not have the capability to recover bodies from the wreck.