This report is a first report of a study into the design efficiency of ships. There is a growing interest in the fuel efficiency of ships because of fuel prices, climate change, and energy security issues. This has resulted in, amongst other things, a regulation governing the design efficiency of new ships. As of 2013, new ships need to meet an EEDI target efficiency relative to a baseline constructed from the average design efficiency of ships that have entered the fleet in the period 1999-2008. The targets become more stringent over time. Currently, the Marine Environment Protection Committee of the International Maritime Organization is reviewing the targets. One of the main questions being addressed is the feasibility of the targets. The historical development of design efficiency can provide relevant information to answer this question in three ways. First, it can elucidate how the design efficiency in the reference line period 1999–2008 compares to other periods. Second, it can show what the timeframe for market driven efficiency improvements has been. And third, it can show which design changes have resulted in efficiency changes.