Interislander now expects the Aratere will sail from Wellington for an Asian dry dock by early February to have two new propeller shafts fitted.
The Cook Strait ferry lost its starboard propeller on November 5 on a night sailing from Picton to Wellington when the shaft snapped just outside Tory Channel, at the top of the Marlborough Sounds.
The propeller was recovered by Seaworks last week and is being examined by Transport Accident Investigation Commission investigators in a Lower Hutt workshop.
Dry-dock options include Singapore, Malaysia, the Philippines and China, Interislander general manager Thomas Davis said.
The company had decided to order replacements for both propeller shafts, as a precautionary measure.
The contract for them had not been finalised.
They would take about 11 weeks to manufacture, and would be transported separately to the dry dock.
The temporary replacement ferry Stena Alegra was making good progress on the voyage south after going through the Panama Canal last weekend, he said.
''We are expecting her to arrive by the end of the month. On its current schedule, December 29 is a possible arrival date.''
Interislander was accepting freight, car and passenger bookings from January 12 for the Stena Alegra.
''If we can sail it sooner, we will,'' Mr Davis said.
''We have a number of regulatory hurdles to go through when the ship gets here. We will have to make sure the berths at both ends work.''
The British-registered Stena Alegra will be in New Zealand for at least six months under the terms of its charter with Interislander.
A shortage of local crew meant Interislander was looking at recruiting some of those now working on the Stena Alegra to remain with it during its stay.
The propeller, which broke off from Aratere in Cook Strait on November 5, was recovered from the seabed by Seaworks last week.
- The Marlborough Express