A union spokesman said it appeared the man had suffered an injury to his arm or wrist, as well as bruising down his body.
Emergency services were called to the Straitsman ferry this morning.
A Wellington Free Ambulance spokeswoman said one person had been taken to Wellington Hospital in a serious condition. She earlier said it was a “multi-agency response”.
A police spokesman confirmed officers responded to an incident at Waterloo Quay, reported at 7.30am.
“It appears one person has sustained serious injuries in an incident involving a truck.”
Inquiries into the incident have begun.
It was a Straitsman staff member who was injured on the main vehicle deck of the ferry, a Maritime New Zealand spokesperson said.
An investigation has been completed, and Maritime NZ has released the ship from where it was held in dock.
The injured man is a member of the Maritime Union. Wellington branch secretary Jim King said he had spoken to the company and representatives were with the man at the hospital.
”Our concern and thoughts are with him and his family.”
A hospital spokesman said the patient was in a stable condition in the emergency department.
Earlier, Bluebridge told passengers on its website that Straitsman sailings were currently delayed by about five hours.
“If you are sailing on Straitsman, you will receive an email and text regarding expected departure and final check-in times.”
The incident is the latest in a string of unfortunate events for the Cook Strait ferry operators.
Bluebridge and Interislander ferries have been hit with breakdowns and engine problems over the past few weeks. Some ferries have broken down part-way through journeys across the strait linking the North and South Islands.
Multiple sailings have been cancelled and thousands of passengers left stranded as both ferry operators are booked to capacity until mid to late March.
The displaced passengers have had to fork out hundreds of dollars for flights - some abandoning their cars with plans to fly back in a month to retrieve them - and others have had to find medium-term accommodation until they can squeeze onto another sailing across the strait.
The ferry shortage is exacerbated by one of Bluebridge’s vessels, the Strait Feronia, being in Sydney for mandatory drydocking, and Interislander’s Kaitaki being freight-only while it is audited after a breakdown.
The Kaitaki breakdown on January 28 sparked a mayday call and dramatic emergency response after the vessel stopped in the middle of Cook Strait.
The Aratere also broke down in the strait near the entrance to the Tory Channel on February 13, leaving the boat apparently adrift as wild weather from Cyclone Gabrielle approached.
