A number of ferry crossings from Yarmouth to Maine have been cancelled. Sailings between May 27-29 will not happen to allow Nova Star Cruises to replace the vessel's Marine Evacuation System. It's considered to be a one time maintenance requirement. The U.S. Coast Guard required Nova Star to activate its MES during an inspection in April. Nova Star has been using a fully operational loaner onboard. It will be switched with Nova Star's system. Guests who have reservations during next week's cancellations will be refunded. The ferry will resume service on May 29, leaving Portland around 10pm for Yarmouth.