The aim of the International Marine Design Conference (IMDC) is to promote all aspects of marine design as an engineering discipline. The 12th IMDC Conference, organized by The University of Tokyo and Yokohama National University, will support and further this aim through a strong technical programme with contributions from both industry and academia around the world. The focus will be on key design challenges and opportunities in today’s rapidly changing maritime marketplace, with special emphasis on sustainable design of vessels and fleet.