"We are looking at increasing the capacity of the Aratere, in order to handle more passengers, vehicles and rail freight on some critical key time gates which are currently capacity constrained," commented Thomas Davis, General Manager for Interislander.

"Aratere features strongly in domestic travel, international tourism and is a key part of New Zealand's rail network. Rail capacity between Auckland and Christchurch is constrained on the Cook Strait with only two rail ferries with limited capacity at key times. Increasing capacity will allow more freight to move by rail on existing trains and ferry sailings improving the productivity of the rail network and removing trucks from the road."

Although options and detailed designs are yet to be finalised, Interislander is currently looking at a 29 metre extension to the ship, currently 150m long. The project would also include a revised bow design.

"The alterations to the hull and bow will improve the way the Aratere cuts through the waves, boosting the ability to achieve on time performance and reducing fuel consumption." added Mr Davis. "The results of initial computer modelling also show that the changes will reduce the wake produced in the Marlborough Sounds by as much as thirty percent."

No final decisions have been reached on the detailed design or timing of project.