Spirit of Tasmania 1 will dock in Hobart today for a four-day layover for an intensive maintenance programme.
More than 40 Tasmanian contractors are involved in the programme.
The ship will leave for Devonport on Monday, before loading freight, passengers and vehicles for Geelong.
On Tuesday, Spirit of Tasmania 2 will depart Geelong for Garden Island in Sydney to spend two weeks in dry dock, also part of the vessel’s scheduled maintenance programme.
Sailing times for Spirit 1 will sail on an amended schedule between Devonport and Geelong until her sister ship returns to the run.
Meanwhile, a Parliamentary committee hearing into delays with the construction of the new Spirits, chaired by Murchison Independent MLC Ruth Forest, will resume on Monday.