This paper describes work done to specify, design and test an offshore intervention vessel for operation off northern Norway and in the Norwegian part of the Barents Sea on an all-year basis. The design has been developed basedon input from manufacturers of subsea systems, owners of offshore vessels and Statoil. Research and development effort have been shared between research institutes (MARINTEK and VTT), the Norwegian University of Science and Technology (NTNU), Statoil, STX OSV and Aker Arctic Technology. The work has been done as a part of the Norwegian Research Council supported project “Construction and intervention vessels for Arctic oil and gas – CIVArctic).