An inquiry has begun after an Interislander cargo ferry hit an unknown object in the Tory Channel.
The Monte Stello veered off-course just inside the channel about 6am on Wednesday and collided with the object.
Interislander general manager Thomas Davis says the incident did not result in any serious damage to the ferry, which continued to Picton and unloaded its cargo.
Mr Davis says the Monte Stello has returned to Wellington where it will be fully assessed.
The Transport Accident Investigation Commission and Interislander are investigating.