BC Ferries has cancelled a round-trip sailing between Prince Rupert and Skidegate next week so that engineers can do a quick fix on the Northern Expedition.Spokesperson Deborah Marshall said the repair work can't wait until the ship's routine refit."The engineers need to do some work on the port shaft generator," she said. "They need to get at a part called the drive end bearing."The work will be done in Prince Rupert, she said.The cancelled sailings are the Monday night, Dec. 12 departure from Rupert, and the Tuesday morning, Dec. 13 departure from Skidegate.The Monday night sailing had 11 passengers, four vehicles and three commercial trailers booked, while the Tuesday sailing had 11 passengers, eight vehicles and four commercial trailers booked. All the customers have been contacted and rebooked, most of them on the Sunday night and Monday morning sailings.Ms Marshall said plenty of room is still available on the other Hecate Strait sailings that week.BC Ferries is also cancelling the Northern Expedition's scheduled sailings for Christmas and Boxing Day. The ferry was to leave Prince Rupert the night of Dec. 25, and leave Skidegate the morning of Dec. 26. Ms Marshall said only two customers were booked on these sailings, and both have been contacted."There was very low demand," she said. BC Ferries has cancelled scheduled sailings that fall on Christmas previously, most recently in 2005, she said.As well, the 7 am and 7:30 am sailings of the Kwuna, between Skidegate and Alliford Bay, have been cancelled for both Christmas Day and New Year's Day. This cancellation happens every year. Service will begin with the 8 am sailing from Alliford Bay.