Once again only one Interislander ferry is able to make the trip across the Cook Strait.

The Kaitaki has a damaged shaft generator - which means it's out of action for the rest of the day.

Exactly one week ago the same ship didn't sail due to different mechanical problems.

The problems have been made worse by the fact that a third ferry, the Arahura, is in dry dock in Auckland for routine maintenance.

Freight and passengers are being transferred to Aratere where possible today.