The port of Auckland would never have been a feasible site for the fishing vessel with two COVID-positive crew to dock, Customs says.
The Viking Bay was been anchored off the coast of Taranaki for almost a week after being denied permission to dock in New Plymouth.
The deep-sea fishing vessel will be moored at Wellington's Queens Wharf from about midday and will will essentially be a quarantine facility for some of the crew, Customs group manager maritime Stephen Waugh said.
Plans for managing its return to shore include not having a local pilot on board to guide it into the harbour. The ship's size meant a local pilot should be required, but authorities have agreed it can arrive without one.
Waugh said the area around the boat would be was cordoned off.
"Once it's alongside we'll then be undertaking testing of all crew at the Queens Wharf before we remove some of the crew off to go into a quarantine facility," he told Morning Report.
Thirteen crew members, including the two people known to have COVID-19, will go into quarantine and seven will stay on the vessel, which is the minimum number required to maintain the ship.
"The concern is what other crew have become infected through contact with those two crew members," Waugh said.
"With COVID, you can't always guarantee that the first negative means no-one has COVID-19, so we will be taking 13 crew off the vessel and leaving a minimum requirement and essentially running a quarantine facility on the vessel as well as moving the other crew to the quarantine facility.
Ports of Auckland agreed to allow the fishing vessel to access its quarantine anchorage, but Waugh said it would not have been a suitable option when they were looking at taking 13 crew off.
"To have it anchored out in the Hauraki Gulf and then essentially medevacing a crew member off each time - it also creates an issue for us when we still have to maintain the vessel and have a crew isolating on board.
"So it was never going to be a feasible option for this."
Waugh said there was very little risk at all to public health.
"Any interaction with the crew by ourselves or health officials will be done within the environment beside the ship and at the time we need to transfer the crew members to the quarantine facility the transportation will be enveloped inside the quarantine area, then the transport will come out of that and go straight to the quarantine facility.
"All of the health officials, customs workers, any of the other stevedores and Centreport workers who are interacting with the vessel have all been vaccinated and we will also be following normal PPE procedures in our activity."
RNZ