Two sailings of the Interislander ferry, the Aratere, have been cancelled due to heavy swells and strong winds in Cook Strait.
KiwiRail said the Aratere's overnight sailings were delayed because of the conditions and the ship was now running behind schedule.
It said the freight-only sailing at 6.45am tomorrow from Wellington and the return sailing at 10.45am from Picton had been cancelled.
KiwiRail said bookings for the sailings were very light and all freight and passengers had been transferred to other services.