The vessel was at a wet dock for general and engineering maintenance.
Interislander fleet marine manager Darryl Wolff said this procedure was nothing out of the ordinary.
"Taking Valentine out of service now for wet dock coincides with the return of Kaitaki to full service — meaning there is freight capacity on our other ships."
The vessel would be docked at Port Chalmers for six to eight weeks while maintenance took place, Mr Wolff said.
"Port Otago provides a safe and secure berth facility and is a good option with a lack of available and suitable berths in Wellington and Picton."
Port Otago commercial manager Craig Usher said the ferry was only for shipping freight and did not transport any passengers.
Finding a birth for the large vessel was quite a feat, but several smaller vessels had been relocated to make room.
Port Otago was not involved in the maintenance itself and individual contractors were likely to be involved, Mr Usher said.
