KiwiRail says it is unable to resume looking for the propeller lost from the Cook Strait ferry Aratere because of a strong southerly swell on Monday.
The propeller was lost from the ferry last Tuesday night and chief executive Jim Quinn says it's important to retrieve the propeller so the cause of its loss can be determined. He says it's also an expensive piece of equipment.
The area to be searched by the New Zealand Diving and Salvage company is two nautical miles from Tory Channel in the Marlborough Sounds.
KiwiRail says that with the Aratere out of commission the remaining two Interislander ferries are working through a backlog of freight and passengers, which will take a week or two.
Mr Quinn says the breakdown couldn't have come at a worse time, at the beginning of the peak summer season.