The Kwuna will be removed from service for four sailings Friday night and Saturday morning, to accommodate overnight mechanical work, BC Ferries has announced.The following sailings on Friday March 28 and Saturday March 29 are cancelled:Leave Alliford Bay 10 pm March 28Leave Skidegate 10:30 pm March 28Leave Alliford Bay 7 am March 29Leave Skidegate 7:30 am March 29Effectively, this means the last sailing on Friday March 28 from Alliford Bay will be at 9:00 pm, the last from Skdiegate at 9:30 pm, with service resuming from Alliford Bay at 8:00 am Saturday, with the first sailing of the morning from Skidegate at 8 am.BC Ferries says the Kwuna needs to change one of its drive legs to get a seal replaced, which is a big enough job to require the cancellations.The Kwuna returned to service in January after a four-month, $5 million refit.