It could be days before stranded passengers bumped from Interislander sailings are rebooked for crossings after a ferry break down, with priority being given to cyclone aid.
Interislaner's Kairahi ferry was taken out service after a problem with its heat exchanger on Monday, leaving people stuck either side of Cook Strait.
The Kaitaki service, which also lost power and got stranded at sea last month, is now only delivering freight. The Aratere is also sailing on Wednesday.
Interislander executive general manager Walter Rushbrook told Checkpoint the Kaiārahi was back in service, departing from Wellington at 4.30pm on Wednesday.
Rushbrook estimated 1200 people on Wednesday and another 1200 on the day before had their bookings cancelled.
"I really apologise for the disruption. It's not just missing the ferry, but it's also onboard connections and other activities [travellers] had planned. We are working very, very hard behind the scenes to make sure we can rebook people as quickly as possible."
They were planning to rebook everyone who wanted it, Rushbrook said. But based on previous disruptions he believed that could take four days or more.
"We're already heavily booked so we've got limited space, so we're cut and shuffling bookings, so we're not immediately able to rebook people but we're working to clear the backlog as quickly as possible."
Emergency supplies coming from the South Island were being given priority, in particular power and communications equipment, he said.
A full refund would be available to those with cancelled bookings, he said.
Meanwhile, Bluebridge said it would return to a normal sailing schedule, with two ships carrying passengers and freight from 1.30pm on Wednesday.
Its Connemara vessel has been undergoing sea trials in the morning after it suffered engine trouble on Friday.
However, the company warned there was almost no available space on other sailings over the coming weeks, and it would not be able to accommodate all cancelled passengers.
New ships for Interislander
Rushbrook reassured travelers they had maintenance and inspection processes in place and would continue investing in them until new ships arrive in 2025.
"The ships have redundant systems so if something goes wrong then there's back-ups, we've got highly trained crew, we're monitoring ... We pick things up and take action quickly and we do have scheduled maintenance periods. So each ship has a time off each week and as we get into the winter season, ships will have longer periods off, including wet docks and dry docks.
"They are getting old, which is why we're getting new ones but we're investing heavily through all those things I mentioned before so make sure we can keep them going until the new ships arrive."
