MS Bluefort is a car/passenger ferry owned by the Cayman Islands-based company Highclere, under conversion into an Accommodation and Repair Vessel thus also known as (ARV). She was built in 1979 by Meyer Werft, Papenburg, Germany as Diana II av Slite for Rederi AB Slite for use in Viking Line's traffic. She has also sailed under the names Diana II, Vironia, Mare Balticum, Meloodia and ARV 1.