This study offers an analysis that connects 2011 in-use fleet characteristics, global satellite data on ship movement, and literature on ship technology to assess the long-term prospects for increasing shipping efficiency. The underlying satellite-based data allows for in-depth knowledge of real-world operational ship speed and its relation to ship efficiency than previous analyses. This analysis also investigates how efficiency characteristics (age, size, technology, operational practices) influence the efficiency of the shipping fleet, and it develops a ship stock turnover model to independently track technical and operational efficiency practices in ships.