The ferry that will temporarily replace the Aratere will not initially be able to take foot passengers because it isn't compatible with the passenger gangways at the terminals.
From January, the Stena Alegra will sail in place of the Aratere, which lost one of its propellors in Cook Strait in November.
On the Interislander website, general manager Thomas Davis says efforts are being made to find a solution to the gangway problems relating to the Stena Alegra.
He says the other inter-island ferries, Kaitaki and Arahura, have plenty of capacity for foot passengers.
The Stena Alegra was one of 20 ships proposed by brokers as a temporary replacement for the Aratere, and was described last month as meeting all of the company's requirements.
It can carry 350 passengers and 78 trucks, while the Aratere is capable of taking 600 passengers and 28 trucks.
