A Royal New Zealand Navy dive team is back at sea in Tonga, trying to find the wreck of a ferry which sank on Wednesday night.
Some 93 people are missing, presumed drowned, after the loss of the Princess Ashika. Fifty four people survived. Two bodies have been found.
Lieutenant Commander Andrew McMillan told Morning Report the divers have identified several positions where the ferry could be, but have not yet found it.
He said the search team was back at sea on Monday morning, but was being hampered by bad weather, but hopes to begin looking for the vessel again at midday.
Lieutenant Commander McMillan said it is an enormous and challenging task, like searching several rugby fields at night-time, or trying to find a small car using only a torch.
He said divers have to continually go back and forth over the search area and the underwater terrain is making the job challenging.
The Princess Ashika is thought to be in about 36 metres of water, about 86km north-east of the Tongan capital. It was en route from Nuku'alofa to the Nomuka Islands group.
Debris is spread over a vast area.
Inquiry to be held
Terms of reference are being drafted for an inquiry into the sinking.
Relatives of the missing are calling for the Tongan government to be more accountable and for Transport Minister Paul Karalus to resign.
Mr Karalus says a consultant from New Zealand, who's in Tonga, will advise how to set up the inquiry.
He says the government wants to ensure the investigation is independent and transparent.
Mr Karalus says the inquiry will be carried out with assistance from New Zealand's Transport Accident Investigation Commission.
The marine consultant from New Zealand, is Michael Eno from Auckland.
Tonga police commander Chris Kelley says the cause of the sinking is still unknown and warns the ferry may never be found.
He says any liability for the ferry sinking will form part of a police investigation, which needs to ultimately look at any criminal culpability.
Tongan Member of Parliament Akilisi Pohiva describes the sinking as "manslaughter by negligence".
He says he had information showing the vessel did not meet safety requirements and was not seaworthy.
Mr Pohiva says he previously raised his concerns about the vessel's safety in Parliament, but did not get a satisfactory response.
National prayer service
A special service of national prayer was held in Nuku'alofa on Sunday. In a rare move, church leaders from many denominations attended.
It was also attended by the royal family, government ministers and personnel from the Australian and New Zealand Defence forces.
In New Zealand, a service at the Tongan Methodist Church in Mangere on Sunday drew about 500 people.