The Interisland ferry Aratere is still undergoing safety tests and won't be back in service until at least Wednesday.
The ship arrived back in New Zealand last week after losing a propellor in November last year and undergoing repairs in Singapore.
KiwiRail said it's been eight months since the crew last sailed the ferry and it needed to ensure the vessel and the crew were ready before it returned to service.
Maritime New Zealand began an audit of the Aratere at the weekend and lifeboat drills and crew preparation were to continue on Tuesday.