Divers are confident the Princess Ashika has been found in the area it sank last Wednesday.
"We are very pleased that we have been able to find the vessel, however very sad to report it's in 110m of water. That means we will not be able to dive on it," dive team head Lieutenant Commander Andrew McMillan of the Royal New Zealand Navy said.
"This will not lead to closure for the Tongan people. Our hearts and sincere condolences go to the families of the victims of the tragedy."
At least 149 people were on board the ferry when it capsized 86km northeast of the Tongan capital of Nuku'alofa. Two bodies and 54 survivors have been found, while 93 people were presumed drowned after being trapped in the vessel.
Sonar images this morning showed a vessel which fitted the general size and shape of the ferry. An oil slick along with other debris and a mooring line also pointed to the Princess Ashika.
The HMNZS Manawanui was due to arrive in Tonga on Saturday with a remotely operated vehicle (ROV) which would provide images of the wreck.
"We are going to put that vehicle down on the deck and literally read the name plates to confirm it is the Princess Ashika," Mr McMillan said.
However, the weather was expected to get worse over the weekend, delaying the operation until Monday.
The surveyor in charge of carrying out checks on the ferry said yesterday it was not seaworthy, but Tongan Transport Minister Paul Karalus has maintained it was. He resigned yesterday but denied he was admitting responsibility.
He said he had resigned because his ministry was the subject of a royal commission of inquiry.
Tonga's Prime Minister Feleti Sevele has announced the sea worthiness of the ferry will be investigated by a commission of inquiry, though he noted that he had himself seen the ferry's certificate of seaworthiness.
Tonight 3 News interviewed the author of a draft report highlighting a litany of structural problems with the vessel.
Willie Vi, a lecturer at the Tongan Maritime School and holder of a New Zealand Foreign Ship Masters Certificate, said the vessel was a death-trap.
"It was like they were just buying a grave," he said. "A portable, floating grave."
Mr Vi said he was given the photos by the shipping company chief executive John Jonesse in April this year, before the vessel was bought in Fiji.
He was asked to put together a report, but he said when he raised concerns with Mr Jonesse about the vessel, they were ignored.
"I told him that the ferry was not suitable for Tongan water because it was built for sheltered waters."
The problems raised in the report included no lashings in the cargo area, no seals over the loading ramps, rusted platforms, and holes.
At the shipping company headquarters Mr Jonesse told 3 News he did fix lashings to the vessel, and dismissed Mr Vi's report as "just a draft".
Mr Jonesse said his highest priority at the moment was helping the families of the victims.
